smack_lsm.c 104.3 KB
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/*
 *  Simplified MAC Kernel (smack) security module
 *
 *  This file contains the smack hook function implementations.
 *
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 *  Authors:
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 *	Casey Schaufler <casey@schaufler-ca.com>
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 *	Jarkko Sakkinen <jarkko.sakkinen@intel.com>
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 *
 *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
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 *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
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 *                Paul Moore <paul@paul-moore.com>
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 *  Copyright (C) 2010 Nokia Corporation
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 *  Copyright (C) 2011 Intel Corporation.
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 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License version 2,
 *      as published by the Free Software Foundation.
 */

#include <linux/xattr.h>
#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/stat.h>
#include <linux/kd.h>
#include <asm/ioctls.h>
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#include <linux/ip.h>
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#include <linux/tcp.h>
#include <linux/udp.h>
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#include <linux/dccp.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
#include <linux/pipe_fs_i.h>
#include <net/cipso_ipv4.h>
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#include <net/ip.h>
#include <net/ipv6.h>
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#include <linux/audit.h>
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#include <linux/magic.h>
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#include <linux/dcache.h>
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#include <linux/personality.h>
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#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/binfmts.h>
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#include "smack.h"

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#define TRANS_TRUE	"TRUE"
#define TRANS_TRUE_SIZE	4

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#define SMK_CONNECTING	0
#define SMK_RECEIVING	1
#define SMK_SENDING	2

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#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
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LIST_HEAD(smk_ipv6_port_list);
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#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
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static struct kmem_cache *smack_inode_cache;
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int smack_enabled;
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#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static void smk_bu_mode(int mode, char *s)
{
	int i = 0;

	if (mode & MAY_READ)
		s[i++] = 'r';
	if (mode & MAY_WRITE)
		s[i++] = 'w';
	if (mode & MAY_EXEC)
		s[i++] = 'x';
	if (mode & MAY_APPEND)
		s[i++] = 'a';
	if (mode & MAY_TRANSMUTE)
		s[i++] = 't';
	if (mode & MAY_LOCK)
		s[i++] = 'l';
	if (i == 0)
		s[i++] = '-';
	s[i] = '\0';
}
#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
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static int smk_bu_note(char *note, struct smack_known *sskp,
		       struct smack_known *oskp, int mode, int rc)
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{
	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
	pr_info("Smack Bringup: (%s %s %s) %s\n",
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		sskp->smk_known, oskp->smk_known, acc, note);
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	return 0;
}
#else
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#define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
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#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
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static int smk_bu_current(char *note, struct smack_known *oskp,
			  int mode, int rc)
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{
	struct task_smack *tsp = current_security();
	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
	pr_info("Smack Bringup: (%s %s %s) %s %s\n",
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		tsp->smk_task->smk_known, oskp->smk_known,
		acc, current->comm, note);
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	return 0;
}
#else
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#define smk_bu_current(note, oskp, mode, RC) (RC)
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#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_task(struct task_struct *otp, int mode, int rc)
{
	struct task_smack *tsp = current_security();
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	struct smack_known *smk_task = smk_of_task_struct(otp);
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	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
	pr_info("Smack Bringup: (%s %s %s) %s to %s\n",
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		tsp->smk_task->smk_known, smk_task->smk_known, acc,
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		current->comm, otp->comm);
	return 0;
}
#else
#define smk_bu_task(otp, mode, RC) (RC)
#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_inode(struct inode *inode, int mode, int rc)
{
	struct task_smack *tsp = current_security();
	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
	pr_info("Smack Bringup: (%s %s %s) inode=(%s %ld) %s\n",
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		tsp->smk_task->smk_known, smk_of_inode(inode)->smk_known, acc,
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		inode->i_sb->s_id, inode->i_ino, current->comm);
	return 0;
}
#else
#define smk_bu_inode(inode, mode, RC) (RC)
#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_file(struct file *file, int mode, int rc)
{
	struct task_smack *tsp = current_security();
	struct smack_known *sskp = tsp->smk_task;
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	struct inode *inode = file_inode(file);
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	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
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	pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
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		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
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		inode->i_sb->s_id, inode->i_ino, file,
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		current->comm);
	return 0;
}
#else
#define smk_bu_file(file, mode, RC) (RC)
#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_credfile(const struct cred *cred, struct file *file,
				int mode, int rc)
{
	struct task_smack *tsp = cred->security;
	struct smack_known *sskp = tsp->smk_task;
	struct inode *inode = file->f_inode;
	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
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	pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
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		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
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		inode->i_sb->s_id, inode->i_ino, file,
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		current->comm);
	return 0;
}
#else
#define smk_bu_credfile(cred, file, mode, RC) (RC)
#endif

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/**
 * smk_fetch - Fetch the smack label from a file.
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 * @name: type of the label (attribute)
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 * @ip: a pointer to the inode
 * @dp: a pointer to the dentry
 *
 * Returns a pointer to the master list entry for the Smack label
 * or NULL if there was no label to fetch.
 */
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static struct smack_known *smk_fetch(const char *name, struct inode *ip,
					struct dentry *dp)
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{
	int rc;
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	char *buffer;
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	struct smack_known *skp = NULL;
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	if (ip->i_op->getxattr == NULL)
		return NULL;

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	buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
	if (buffer == NULL)
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		return NULL;

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	rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
	if (rc > 0)
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		skp = smk_import_entry(buffer, rc);
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	kfree(buffer);

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	return skp;
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}

/**
 * new_inode_smack - allocate an inode security blob
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 * @skp: a pointer to the Smack label entry to use in the blob
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 *
 * Returns the new blob or NULL if there's no memory available
 */
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struct inode_smack *new_inode_smack(struct smack_known *skp)
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{
	struct inode_smack *isp;

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	isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS);
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	if (isp == NULL)
		return NULL;

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	isp->smk_inode = skp;
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	isp->smk_flags = 0;
	mutex_init(&isp->smk_lock);

	return isp;
}

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/**
 * new_task_smack - allocate a task security blob
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 * @task: a pointer to the Smack label for the running task
 * @forked: a pointer to the Smack label for the forked task
 * @gfp: type of the memory for the allocation
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 *
 * Returns the new blob or NULL if there's no memory available
 */
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static struct task_smack *new_task_smack(struct smack_known *task,
					struct smack_known *forked, gfp_t gfp)
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{
	struct task_smack *tsp;

	tsp = kzalloc(sizeof(struct task_smack), gfp);
	if (tsp == NULL)
		return NULL;

	tsp->smk_task = task;
	tsp->smk_forked = forked;
	INIT_LIST_HEAD(&tsp->smk_rules);
	mutex_init(&tsp->smk_rules_lock);

	return tsp;
}

/**
 * smk_copy_rules - copy a rule set
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 * @nhead: new rules header pointer
 * @ohead: old rules header pointer
 * @gfp: type of the memory for the allocation
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 *
 * Returns 0 on success, -ENOMEM on error
 */
static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
				gfp_t gfp)
{
	struct smack_rule *nrp;
	struct smack_rule *orp;
	int rc = 0;

	INIT_LIST_HEAD(nhead);

	list_for_each_entry_rcu(orp, ohead, list) {
		nrp = kzalloc(sizeof(struct smack_rule), gfp);
		if (nrp == NULL) {
			rc = -ENOMEM;
			break;
		}
		*nrp = *orp;
		list_add_rcu(&nrp->list, nhead);
	}
	return rc;
}

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/**
 * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
 * @mode - input mode in form of PTRACE_MODE_*
 *
 * Returns a converted MAY_* mode usable by smack rules
 */
static inline unsigned int smk_ptrace_mode(unsigned int mode)
{
	switch (mode) {
	case PTRACE_MODE_READ:
		return MAY_READ;
	case PTRACE_MODE_ATTACH:
		return MAY_READWRITE;
	}

	return 0;
}

/**
 * smk_ptrace_rule_check - helper for ptrace access
 * @tracer: tracer process
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 * @tracee_known: label entry of the process that's about to be traced
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 * @mode: ptrace attachment mode (PTRACE_MODE_*)
 * @func: name of the function that called us, used for audit
 *
 * Returns 0 on access granted, -error on error
 */
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static int smk_ptrace_rule_check(struct task_struct *tracer,
				 struct smack_known *tracee_known,
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				 unsigned int mode, const char *func)
{
	int rc;
	struct smk_audit_info ad, *saip = NULL;
	struct task_smack *tsp;
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	struct smack_known *tracer_known;
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	if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
		smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
		smk_ad_setfield_u_tsk(&ad, tracer);
		saip = &ad;
	}

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	rcu_read_lock();
	tsp = __task_cred(tracer)->security;
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	tracer_known = smk_of_task(tsp);
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	if ((mode & PTRACE_MODE_ATTACH) &&
	    (smack_ptrace_rule == SMACK_PTRACE_EXACT ||
	     smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
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		if (tracer_known->smk_known == tracee_known->smk_known)
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			rc = 0;
		else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
			rc = -EACCES;
		else if (capable(CAP_SYS_PTRACE))
			rc = 0;
		else
			rc = -EACCES;

		if (saip)
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			smack_log(tracer_known->smk_known,
				  tracee_known->smk_known,
				  0, rc, saip);
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		rcu_read_unlock();
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		return rc;
	}

	/* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
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	rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
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	rcu_read_unlock();
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	return rc;
}

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/*
 * LSM hooks.
 * We he, that is fun!
 */

/**
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 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
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 * @ctp: child task pointer
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 * @mode: ptrace attachment mode (PTRACE_MODE_*)
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 *
 * Returns 0 if access is OK, an error code otherwise
 *
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 * Do the capability checks.
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 */
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static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
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{
	int rc;
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	struct smack_known *skp;
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	rc = cap_ptrace_access_check(ctp, mode);
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	if (rc != 0)
		return rc;

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	skp = smk_of_task_struct(ctp);
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	rc = smk_ptrace_rule_check(current, skp, mode, __func__);
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	return rc;
}

/**
 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
 * @ptp: parent task pointer
 *
 * Returns 0 if access is OK, an error code otherwise
 *
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 * Do the capability checks, and require PTRACE_MODE_ATTACH.
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 */
static int smack_ptrace_traceme(struct task_struct *ptp)
{
	int rc;
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	struct smack_known *skp;
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	rc = cap_ptrace_traceme(ptp);
	if (rc != 0)
		return rc;
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	skp = smk_of_task(current_security());
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	rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
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	return rc;
}

/**
 * smack_syslog - Smack approval on syslog
 * @type: message type
 *
 * Returns 0 on success, error code otherwise.
 */
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static int smack_syslog(int typefrom_file)
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{
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	int rc = 0;
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	struct smack_known *skp = smk_of_current();
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	if (smack_privileged(CAP_MAC_OVERRIDE))
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		return 0;

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	if (smack_syslog_label != NULL && smack_syslog_label != skp)
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		rc = -EACCES;

	return rc;
}


/*
 * Superblock Hooks.
 */

/**
 * smack_sb_alloc_security - allocate a superblock blob
 * @sb: the superblock getting the blob
 *
 * Returns 0 on success or -ENOMEM on error.
 */
static int smack_sb_alloc_security(struct super_block *sb)
{
	struct superblock_smack *sbsp;

	sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);

	if (sbsp == NULL)
		return -ENOMEM;

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	sbsp->smk_root = &smack_known_floor;
	sbsp->smk_default = &smack_known_floor;
	sbsp->smk_floor = &smack_known_floor;
	sbsp->smk_hat = &smack_known_hat;
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	/*
	 * smk_initialized will be zero from kzalloc.
	 */
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	sb->s_security = sbsp;

	return 0;
}

/**
 * smack_sb_free_security - free a superblock blob
 * @sb: the superblock getting the blob
 *
 */
static void smack_sb_free_security(struct super_block *sb)
{
	kfree(sb->s_security);
	sb->s_security = NULL;
}

/**
 * smack_sb_copy_data - copy mount options data for processing
 * @orig: where to start
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 * @smackopts: mount options string
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 *
 * Returns 0 on success or -ENOMEM on error.
 *
 * Copy the Smack specific mount options out of the mount
 * options list.
 */
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static int smack_sb_copy_data(char *orig, char *smackopts)
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{
	char *cp, *commap, *otheropts, *dp;

	otheropts = (char *)get_zeroed_page(GFP_KERNEL);
	if (otheropts == NULL)
		return -ENOMEM;

	for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
		if (strstr(cp, SMK_FSDEFAULT) == cp)
			dp = smackopts;
		else if (strstr(cp, SMK_FSFLOOR) == cp)
			dp = smackopts;
		else if (strstr(cp, SMK_FSHAT) == cp)
			dp = smackopts;
		else if (strstr(cp, SMK_FSROOT) == cp)
			dp = smackopts;
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		else if (strstr(cp, SMK_FSTRANS) == cp)
			dp = smackopts;
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		else
			dp = otheropts;

		commap = strchr(cp, ',');
		if (commap != NULL)
			*commap = '\0';

		if (*dp != '\0')
			strcat(dp, ",");
		strcat(dp, cp);
	}

	strcpy(orig, otheropts);
	free_page((unsigned long)otheropts);

	return 0;
}

/**
 * smack_sb_kern_mount - Smack specific mount processing
 * @sb: the file system superblock
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 * @flags: the mount flags
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 * @data: the smack mount options
 *
 * Returns 0 on success, an error code on failure
 */
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static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
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{
	struct dentry *root = sb->s_root;
	struct inode *inode = root->d_inode;
	struct superblock_smack *sp = sb->s_security;
	struct inode_smack *isp;
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	struct smack_known *skp;
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	char *op;
	char *commap;
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	int transmute = 0;
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	int specified = 0;
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	if (sp->smk_initialized)
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		return 0;
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	sp->smk_initialized = 1;

	for (op = data; op != NULL; op = commap) {
		commap = strchr(op, ',');
		if (commap != NULL)
			*commap++ = '\0';

		if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
			op += strlen(SMK_FSHAT);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_hat = skp;
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				specified = 1;
			}
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		} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
			op += strlen(SMK_FSFLOOR);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_floor = skp;
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				specified = 1;
			}
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		} else if (strncmp(op, SMK_FSDEFAULT,
				   strlen(SMK_FSDEFAULT)) == 0) {
			op += strlen(SMK_FSDEFAULT);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_default = skp;
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				specified = 1;
			}
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		} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
			op += strlen(SMK_FSROOT);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_root = skp;
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				specified = 1;
			}
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		} else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
			op += strlen(SMK_FSTRANS);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_root = skp;
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				transmute = 1;
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				specified = 1;
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			}
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		}
	}

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	if (!smack_privileged(CAP_MAC_ADMIN)) {
		/*
		 * Unprivileged mounts don't get to specify Smack values.
		 */
		if (specified)
			return -EPERM;
		/*
		 * Unprivileged mounts get root and default from the caller.
		 */
		skp = smk_of_current();
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		sp->smk_root = skp;
		sp->smk_default = skp;
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	}
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	/*
	 * Initialize the root inode.
	 */
	isp = inode->i_security;
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	if (isp == NULL) {
		isp = new_inode_smack(sp->smk_root);
		if (isp == NULL)
			return -ENOMEM;
		inode->i_security = isp;
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	} else
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		isp->smk_inode = sp->smk_root;

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	if (transmute)
		isp->smk_flags |= SMK_INODE_TRANSMUTE;

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	return 0;
}

/**
 * smack_sb_statfs - Smack check on statfs
 * @dentry: identifies the file system in question
 *
 * Returns 0 if current can read the floor of the filesystem,
 * and error code otherwise
 */
static int smack_sb_statfs(struct dentry *dentry)
{
	struct superblock_smack *sbp = dentry->d_sb->s_security;
E
Etienne Basset 已提交
658 659 660
	int rc;
	struct smk_audit_info ad;

661
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
662
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
663

E
Etienne Basset 已提交
664
	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
C
Casey Schaufler 已提交
665
	rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
E
Etienne Basset 已提交
666
	return rc;
667 668
}

669 670 671 672
/*
 * BPRM hooks
 */

C
Casey Schaufler 已提交
673 674 675 676
/**
 * smack_bprm_set_creds - set creds for exec
 * @bprm: the exec information
 *
677
 * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
C
Casey Schaufler 已提交
678
 */
679 680
static int smack_bprm_set_creds(struct linux_binprm *bprm)
{
A
Al Viro 已提交
681
	struct inode *inode = file_inode(bprm->file);
682
	struct task_smack *bsp = bprm->cred->security;
683 684 685 686 687 688 689 690 691 692
	struct inode_smack *isp;
	int rc;

	rc = cap_bprm_set_creds(bprm);
	if (rc != 0)
		return rc;

	if (bprm->cred_prepared)
		return 0;

693 694
	isp = inode->i_security;
	if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
695 696
		return 0;

697 698 699 700 701 702 703 704
	if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
		struct task_struct *tracer;
		rc = 0;

		rcu_read_lock();
		tracer = ptrace_parent(current);
		if (likely(tracer != NULL))
			rc = smk_ptrace_rule_check(tracer,
705
						   isp->smk_task,
706 707 708 709 710 711 712
						   PTRACE_MODE_ATTACH,
						   __func__);
		rcu_read_unlock();

		if (rc != 0)
			return rc;
	} else if (bprm->unsafe)
713
		return -EPERM;
714

715 716
	bsp->smk_task = isp->smk_task;
	bprm->per_clear |= PER_CLEAR_ON_SETID;
717

718 719
	return 0;
}
720

721 722 723 724 725 726 727 728 729
/**
 * smack_bprm_committing_creds - Prepare to install the new credentials
 * from bprm.
 *
 * @bprm: binprm for exec
 */
static void smack_bprm_committing_creds(struct linux_binprm *bprm)
{
	struct task_smack *bsp = bprm->cred->security;
730

731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749
	if (bsp->smk_task != bsp->smk_forked)
		current->pdeath_signal = 0;
}

/**
 * smack_bprm_secureexec - Return the decision to use secureexec.
 * @bprm: binprm for exec
 *
 * Returns 0 on success.
 */
static int smack_bprm_secureexec(struct linux_binprm *bprm)
{
	struct task_smack *tsp = current_security();
	int ret = cap_bprm_secureexec(bprm);

	if (!ret && (tsp->smk_task != tsp->smk_forked))
		ret = 1;

	return ret;
750 751
}

752 753 754 755 756 757
/*
 * Inode hooks
 */

/**
 * smack_inode_alloc_security - allocate an inode blob
758
 * @inode: the inode in need of a blob
759 760 761 762 763
 *
 * Returns 0 if it gets a blob, -ENOMEM otherwise
 */
static int smack_inode_alloc_security(struct inode *inode)
{
764 765
	struct smack_known *skp = smk_of_current();

766
	inode->i_security = new_inode_smack(skp);
767 768 769 770 771 772 773
	if (inode->i_security == NULL)
		return -ENOMEM;
	return 0;
}

/**
 * smack_inode_free_security - free an inode blob
774
 * @inode: the inode with a blob
775 776 777 778 779
 *
 * Clears the blob pointer in inode
 */
static void smack_inode_free_security(struct inode *inode)
{
780
	kmem_cache_free(smack_inode_cache, inode->i_security);
781 782 783 784 785
	inode->i_security = NULL;
}

/**
 * smack_inode_init_security - copy out the smack from an inode
786 787
 * @inode: the newly created inode
 * @dir: containing directory object
788
 * @qstr: unused
789 790 791 792 793 794 795
 * @name: where to put the attribute name
 * @value: where to put the attribute value
 * @len: where to put the length of the attribute
 *
 * Returns 0 if it all works out, -ENOMEM if there's no memory
 */
static int smack_inode_init_security(struct inode *inode, struct inode *dir,
796
				     const struct qstr *qstr, const char **name,
797
				     void **value, size_t *len)
798
{
C
Casey Schaufler 已提交
799
	struct inode_smack *issp = inode->i_security;
800
	struct smack_known *skp = smk_of_current();
801 802
	struct smack_known *isp = smk_of_inode(inode);
	struct smack_known *dsp = smk_of_inode(dir);
803
	int may;
804

805 806
	if (name)
		*name = XATTR_SMACK_SUFFIX;
807

808
	if (value && len) {
809
		rcu_read_lock();
810 811
		may = smk_access_entry(skp->smk_known, dsp->smk_known,
				       &skp->smk_rules);
812
		rcu_read_unlock();
813 814 815 816 817

		/*
		 * If the access rule allows transmutation and
		 * the directory requests transmutation then
		 * by all means transmute.
C
Casey Schaufler 已提交
818
		 * Mark the inode as changed.
819
		 */
820
		if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
C
Casey Schaufler 已提交
821
		    smk_inode_transmutable(dir)) {
822
			isp = dsp;
C
Casey Schaufler 已提交
823 824
			issp->smk_flags |= SMK_INODE_CHANGED;
		}
825

826
		*value = kstrdup(isp->smk_known, GFP_NOFS);
827 828 829
		if (*value == NULL)
			return -ENOMEM;

830
		*len = strlen(isp->smk_known);
831
	}
832 833 834 835 836 837 838 839 840 841 842 843 844 845 846

	return 0;
}

/**
 * smack_inode_link - Smack check on link
 * @old_dentry: the existing object
 * @dir: unused
 * @new_dentry: the new object
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
			    struct dentry *new_dentry)
{
847
	struct smack_known *isp;
E
Etienne Basset 已提交
848 849 850
	struct smk_audit_info ad;
	int rc;

851
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
852
	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
853 854

	isp = smk_of_inode(old_dentry->d_inode);
E
Etienne Basset 已提交
855
	rc = smk_curacc(isp, MAY_WRITE, &ad);
C
Casey Schaufler 已提交
856
	rc = smk_bu_inode(old_dentry->d_inode, MAY_WRITE, rc);
857

858
	if (rc == 0 && d_is_positive(new_dentry)) {
859
		isp = smk_of_inode(new_dentry->d_inode);
E
Etienne Basset 已提交
860 861
		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
		rc = smk_curacc(isp, MAY_WRITE, &ad);
C
Casey Schaufler 已提交
862
		rc = smk_bu_inode(new_dentry->d_inode, MAY_WRITE, rc);
863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878
	}

	return rc;
}

/**
 * smack_inode_unlink - Smack check on inode deletion
 * @dir: containing directory object
 * @dentry: file to unlink
 *
 * Returns 0 if current can write the containing directory
 * and the object, error code otherwise
 */
static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
{
	struct inode *ip = dentry->d_inode;
E
Etienne Basset 已提交
879
	struct smk_audit_info ad;
880 881
	int rc;

882
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
883 884
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

885 886 887
	/*
	 * You need write access to the thing you're unlinking
	 */
E
Etienne Basset 已提交
888
	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
889
	rc = smk_bu_inode(ip, MAY_WRITE, rc);
E
Etienne Basset 已提交
890
	if (rc == 0) {
891 892 893
		/*
		 * You also need write access to the containing directory
		 */
894
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
E
Etienne Basset 已提交
895 896
		smk_ad_setfield_u_fs_inode(&ad, dir);
		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
897
		rc = smk_bu_inode(dir, MAY_WRITE, rc);
E
Etienne Basset 已提交
898
	}
899 900 901 902 903 904 905 906 907 908 909 910 911
	return rc;
}

/**
 * smack_inode_rmdir - Smack check on directory deletion
 * @dir: containing directory object
 * @dentry: directory to unlink
 *
 * Returns 0 if current can write the containing directory
 * and the directory, error code otherwise
 */
static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
{
E
Etienne Basset 已提交
912
	struct smk_audit_info ad;
913 914
	int rc;

915
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
916 917
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

918 919 920
	/*
	 * You need write access to the thing you're removing
	 */
E
Etienne Basset 已提交
921
	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
922
	rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
E
Etienne Basset 已提交
923
	if (rc == 0) {
924 925 926
		/*
		 * You also need write access to the containing directory
		 */
927
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
E
Etienne Basset 已提交
928 929
		smk_ad_setfield_u_fs_inode(&ad, dir);
		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
930
		rc = smk_bu_inode(dir, MAY_WRITE, rc);
E
Etienne Basset 已提交
931
	}
932 933 934 935 936 937

	return rc;
}

/**
 * smack_inode_rename - Smack check on rename
938 939 940 941
 * @old_inode: unused
 * @old_dentry: the old object
 * @new_inode: unused
 * @new_dentry: the new object
942 943 944 945 946 947 948 949 950 951 952 953
 *
 * Read and write access is required on both the old and
 * new directories.
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
static int smack_inode_rename(struct inode *old_inode,
			      struct dentry *old_dentry,
			      struct inode *new_inode,
			      struct dentry *new_dentry)
{
	int rc;
954
	struct smack_known *isp;
E
Etienne Basset 已提交
955 956
	struct smk_audit_info ad;

957
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
958
	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
959 960

	isp = smk_of_inode(old_dentry->d_inode);
E
Etienne Basset 已提交
961
	rc = smk_curacc(isp, MAY_READWRITE, &ad);
C
Casey Schaufler 已提交
962
	rc = smk_bu_inode(old_dentry->d_inode, MAY_READWRITE, rc);
963

964
	if (rc == 0 && d_is_positive(new_dentry)) {
965
		isp = smk_of_inode(new_dentry->d_inode);
E
Etienne Basset 已提交
966 967
		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
		rc = smk_curacc(isp, MAY_READWRITE, &ad);
C
Casey Schaufler 已提交
968
		rc = smk_bu_inode(new_dentry->d_inode, MAY_READWRITE, rc);
969 970 971 972 973 974 975 976 977 978 979 980 981
	}
	return rc;
}

/**
 * smack_inode_permission - Smack version of permission()
 * @inode: the inode in question
 * @mask: the access requested
 *
 * This is the important Smack hook.
 *
 * Returns 0 if access is permitted, -EACCES otherwise
 */
982
static int smack_inode_permission(struct inode *inode, int mask)
983
{
E
Etienne Basset 已提交
984
	struct smk_audit_info ad;
985
	int no_block = mask & MAY_NOT_BLOCK;
C
Casey Schaufler 已提交
986
	int rc;
987 988

	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
989 990 991 992 993
	/*
	 * No permission to check. Existence test. Yup, it's there.
	 */
	if (mask == 0)
		return 0;
994 995

	/* May be droppable after audit */
996
	if (no_block)
997
		return -ECHILD;
998
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
E
Etienne Basset 已提交
999
	smk_ad_setfield_u_fs_inode(&ad, inode);
C
Casey Schaufler 已提交
1000 1001 1002
	rc = smk_curacc(smk_of_inode(inode), mask, &ad);
	rc = smk_bu_inode(inode, mask, rc);
	return rc;
1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013
}

/**
 * smack_inode_setattr - Smack check for setting attributes
 * @dentry: the object
 * @iattr: for the force flag
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
E
Etienne Basset 已提交
1014
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1015 1016
	int rc;

1017 1018 1019 1020 1021
	/*
	 * Need to allow for clearing the setuid bit.
	 */
	if (iattr->ia_valid & ATTR_FORCE)
		return 0;
1022
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1023
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1024

C
Casey Schaufler 已提交
1025 1026 1027
	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
	rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
	return rc;
1028 1029 1030 1031
}

/**
 * smack_inode_getattr - Smack check for getting attributes
1032
 * @mnt: vfsmount of the object
1033 1034 1035 1036
 * @dentry: the object
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1037
static int smack_inode_getattr(const struct path *path)
1038
{
E
Etienne Basset 已提交
1039
	struct smk_audit_info ad;
1040
	struct inode *inode = path->dentry->d_inode;
C
Casey Schaufler 已提交
1041
	int rc;
E
Etienne Basset 已提交
1042

1043
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1044 1045 1046
	smk_ad_setfield_u_fs_path(&ad, *path);
	rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
	rc = smk_bu_inode(inode, MAY_READ, rc);
C
Casey Schaufler 已提交
1047
	return rc;
1048 1049 1050 1051 1052 1053
}

/**
 * smack_inode_setxattr - Smack check for setting xattrs
 * @dentry: the object
 * @name: name of the attribute
1054 1055
 * @value: value of the attribute
 * @size: size of the value
1056 1057 1058 1059 1060 1061
 * @flags: unused
 *
 * This protects the Smack attribute explicitly.
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1062 1063
static int smack_inode_setxattr(struct dentry *dentry, const char *name,
				const void *value, size_t size, int flags)
1064
{
E
Etienne Basset 已提交
1065
	struct smk_audit_info ad;
1066 1067 1068 1069
	struct smack_known *skp;
	int check_priv = 0;
	int check_import = 0;
	int check_star = 0;
1070
	int rc = 0;
1071

1072 1073 1074
	/*
	 * Check label validity here so import won't fail in post_setxattr
	 */
1075 1076
	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1077 1078 1079 1080 1081 1082 1083 1084
	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
		check_priv = 1;
		check_import = 1;
	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
		   strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
		check_priv = 1;
		check_import = 1;
		check_star = 1;
1085
	} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1086
		check_priv = 1;
1087 1088 1089
		if (size != TRANS_TRUE_SIZE ||
		    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
			rc = -EINVAL;
1090 1091 1092
	} else
		rc = cap_inode_setxattr(dentry, name, value, size, flags);

1093 1094 1095 1096
	if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
		rc = -EPERM;

	if (rc == 0 && check_import) {
1097
		skp = size ? smk_import_entry(value, size) : NULL;
1098 1099 1100 1101 1102
		if (skp == NULL || (check_star &&
		    (skp == &smack_known_star || skp == &smack_known_web)))
			rc = -EINVAL;
	}

1103
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1104 1105
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

C
Casey Schaufler 已提交
1106
	if (rc == 0) {
E
Etienne Basset 已提交
1107
		rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1108 1109
		rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
	}
1110 1111

	return rc;
1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124
}

/**
 * smack_inode_post_setxattr - Apply the Smack update approved above
 * @dentry: object
 * @name: attribute name
 * @value: attribute value
 * @size: attribute size
 * @flags: unused
 *
 * Set the pointer in the inode blob to the entry found
 * in the master label list.
 */
1125 1126
static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
				      const void *value, size_t size, int flags)
1127
{
1128
	struct smack_known *skp;
1129
	struct inode_smack *isp = dentry->d_inode->i_security;
1130

1131 1132 1133 1134 1135
	if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
		isp->smk_flags |= SMK_INODE_TRANSMUTE;
		return;
	}

1136
	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1137
		skp = smk_import_entry(value, size);
1138
		if (skp != NULL)
1139
			isp->smk_inode = skp;
1140
		else
1141
			isp->smk_inode = &smack_known_invalid;
1142
	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
1143
		skp = smk_import_entry(value, size);
1144 1145
		if (skp != NULL)
			isp->smk_task = skp;
1146
		else
1147
			isp->smk_task = &smack_known_invalid;
1148
	} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1149
		skp = smk_import_entry(value, size);
1150 1151
		if (skp != NULL)
			isp->smk_mmap = skp;
1152
		else
1153 1154
			isp->smk_mmap = &smack_known_invalid;
	}
1155 1156 1157 1158

	return;
}

C
Casey Schaufler 已提交
1159
/**
1160 1161 1162 1163 1164 1165
 * smack_inode_getxattr - Smack check on getxattr
 * @dentry: the object
 * @name: unused
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1166
static int smack_inode_getxattr(struct dentry *dentry, const char *name)
1167
{
E
Etienne Basset 已提交
1168
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1169
	int rc;
E
Etienne Basset 已提交
1170

1171
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1172 1173
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

C
Casey Schaufler 已提交
1174 1175 1176
	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
	rc = smk_bu_inode(dentry->d_inode, MAY_READ, rc);
	return rc;
1177 1178
}

C
Casey Schaufler 已提交
1179
/**
1180 1181 1182 1183 1184 1185 1186 1187
 * smack_inode_removexattr - Smack check on removexattr
 * @dentry: the object
 * @name: name of the attribute
 *
 * Removing the Smack attribute requires CAP_MAC_ADMIN
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1188
static int smack_inode_removexattr(struct dentry *dentry, const char *name)
1189
{
1190
	struct inode_smack *isp;
E
Etienne Basset 已提交
1191
	struct smk_audit_info ad;
1192
	int rc = 0;
1193

1194 1195
	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1196
	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
1197
	    strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1198
	    strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
P
Pankaj Kumar 已提交
1199
	    strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1200
		if (!smack_privileged(CAP_MAC_ADMIN))
1201 1202 1203 1204
			rc = -EPERM;
	} else
		rc = cap_inode_removexattr(dentry, name);

1205 1206 1207
	if (rc != 0)
		return rc;

1208
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1209
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1210

1211
	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1212
	rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223
	if (rc != 0)
		return rc;

	isp = dentry->d_inode->i_security;
	/*
	 * Don't do anything special for these.
	 *	XATTR_NAME_SMACKIPIN
	 *	XATTR_NAME_SMACKIPOUT
	 *	XATTR_NAME_SMACKEXEC
	 */
	if (strcmp(name, XATTR_NAME_SMACK) == 0)
1224
		isp->smk_task = NULL;
1225
	else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
1226
		isp->smk_mmap = NULL;
1227 1228
	else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
		isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
1229

1230
	return 0;
1231 1232 1233 1234 1235 1236 1237
}

/**
 * smack_inode_getsecurity - get smack xattrs
 * @inode: the object
 * @name: attribute name
 * @buffer: where to put the result
1238
 * @alloc: unused
1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249
 *
 * Returns the size of the attribute or an error code
 */
static int smack_inode_getsecurity(const struct inode *inode,
				   const char *name, void **buffer,
				   bool alloc)
{
	struct socket_smack *ssp;
	struct socket *sock;
	struct super_block *sbp;
	struct inode *ip = (struct inode *)inode;
1250
	struct smack_known *isp;
1251 1252 1253 1254 1255
	int ilen;
	int rc = 0;

	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
		isp = smk_of_inode(inode);
1256 1257
		ilen = strlen(isp->smk_known);
		*buffer = isp->smk_known;
1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268
		return ilen;
	}

	/*
	 * The rest of the Smack xattrs are only on sockets.
	 */
	sbp = ip->i_sb;
	if (sbp->s_magic != SOCKFS_MAGIC)
		return -EOPNOTSUPP;

	sock = SOCKET_I(ip);
1269
	if (sock == NULL || sock->sk == NULL)
1270 1271 1272 1273 1274
		return -EOPNOTSUPP;

	ssp = sock->sk->sk_security;

	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1275
		isp = ssp->smk_in;
1276
	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
1277
		isp = ssp->smk_out;
1278 1279 1280
	else
		return -EOPNOTSUPP;

1281
	ilen = strlen(isp->smk_known);
1282
	if (rc == 0) {
1283
		*buffer = isp->smk_known;
1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301
		rc = ilen;
	}

	return rc;
}


/**
 * smack_inode_listsecurity - list the Smack attributes
 * @inode: the object
 * @buffer: where they go
 * @buffer_size: size of buffer
 *
 * Returns 0 on success, -EINVAL otherwise
 */
static int smack_inode_listsecurity(struct inode *inode, char *buffer,
				    size_t buffer_size)
{
1302
	int len = sizeof(XATTR_NAME_SMACK);
1303

1304
	if (buffer != NULL && len <= buffer_size)
1305
		memcpy(buffer, XATTR_NAME_SMACK, len);
1306 1307

	return len;
1308 1309
}

1310 1311 1312 1313 1314 1315 1316 1317 1318
/**
 * smack_inode_getsecid - Extract inode's security id
 * @inode: inode to extract the info from
 * @secid: where result will be saved
 */
static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
{
	struct inode_smack *isp = inode->i_security;

1319
	*secid = isp->smk_inode->smk_secid;
1320 1321
}

1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351
/*
 * File Hooks
 */

/**
 * smack_file_permission - Smack check on file operations
 * @file: unused
 * @mask: unused
 *
 * Returns 0
 *
 * Should access checks be done on each read or write?
 * UNICOS and SELinux say yes.
 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
 *
 * I'll say no for now. Smack does not do the frequent
 * label changing that SELinux does.
 */
static int smack_file_permission(struct file *file, int mask)
{
	return 0;
}

/**
 * smack_file_alloc_security - assign a file security blob
 * @file: the object
 *
 * The security blob for a file is a pointer to the master
 * label list, so no allocation is done.
 *
C
Casey Schaufler 已提交
1352 1353 1354
 * f_security is the owner security information. It
 * isn't used on file access checks, it's for send_sigio.
 *
1355 1356 1357 1358
 * Returns 0
 */
static int smack_file_alloc_security(struct file *file)
{
1359 1360
	struct smack_known *skp = smk_of_current();

1361
	file->f_security = skp;
1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390
	return 0;
}

/**
 * smack_file_free_security - clear a file security blob
 * @file: the object
 *
 * The security blob for a file is a pointer to the master
 * label list, so no memory is freed.
 */
static void smack_file_free_security(struct file *file)
{
	file->f_security = NULL;
}

/**
 * smack_file_ioctl - Smack check on ioctls
 * @file: the object
 * @cmd: what to do
 * @arg: unused
 *
 * Relies heavily on the correct use of the ioctl command conventions.
 *
 * Returns 0 if allowed, error code otherwise
 */
static int smack_file_ioctl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
	int rc = 0;
E
Etienne Basset 已提交
1391
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1392
	struct inode *inode = file_inode(file);
E
Etienne Basset 已提交
1393

1394
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
E
Etienne Basset 已提交
1395
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1396

C
Casey Schaufler 已提交
1397
	if (_IOC_DIR(cmd) & _IOC_WRITE) {
C
Casey Schaufler 已提交
1398
		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1399 1400
		rc = smk_bu_file(file, MAY_WRITE, rc);
	}
1401

C
Casey Schaufler 已提交
1402
	if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
C
Casey Schaufler 已提交
1403
		rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
C
Casey Schaufler 已提交
1404 1405
		rc = smk_bu_file(file, MAY_READ, rc);
	}
1406 1407 1408 1409 1410 1411 1412

	return rc;
}

/**
 * smack_file_lock - Smack check on file locking
 * @file: the object
1413
 * @cmd: unused
1414
 *
1415
 * Returns 0 if current has lock access, error code otherwise
1416 1417 1418
 */
static int smack_file_lock(struct file *file, unsigned int cmd)
{
E
Etienne Basset 已提交
1419
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1420
	int rc;
C
Casey Schaufler 已提交
1421
	struct inode *inode = file_inode(file);
E
Etienne Basset 已提交
1422

1423 1424
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
C
Casey Schaufler 已提交
1425
	rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
C
Casey Schaufler 已提交
1426 1427
	rc = smk_bu_file(file, MAY_LOCK, rc);
	return rc;
1428 1429 1430 1431 1432 1433 1434 1435
}

/**
 * smack_file_fcntl - Smack check on fcntl
 * @file: the object
 * @cmd: what action to check
 * @arg: unused
 *
1436 1437 1438 1439
 * Generally these operations are harmless.
 * File locking operations present an obvious mechanism
 * for passing information, so they require write access.
 *
1440 1441 1442 1443 1444
 * Returns 0 if current has access, error code otherwise
 */
static int smack_file_fcntl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
E
Etienne Basset 已提交
1445
	struct smk_audit_info ad;
1446
	int rc = 0;
C
Casey Schaufler 已提交
1447
	struct inode *inode = file_inode(file);
E
Etienne Basset 已提交
1448

1449 1450
	switch (cmd) {
	case F_GETLK:
1451
		break;
1452 1453
	case F_SETLK:
	case F_SETLKW:
1454 1455
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
		smk_ad_setfield_u_fs_path(&ad, file->f_path);
C
Casey Schaufler 已提交
1456
		rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
C
Casey Schaufler 已提交
1457
		rc = smk_bu_file(file, MAY_LOCK, rc);
1458
		break;
1459 1460
	case F_SETOWN:
	case F_SETSIG:
1461 1462
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
		smk_ad_setfield_u_fs_path(&ad, file->f_path);
C
Casey Schaufler 已提交
1463
		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1464
		rc = smk_bu_file(file, MAY_WRITE, rc);
1465 1466
		break;
	default:
1467
		break;
1468 1469 1470 1471 1472
	}

	return rc;
}

1473
/**
1474
 * smack_mmap_file :
1475 1476 1477 1478 1479 1480 1481 1482
 * Check permissions for a mmap operation.  The @file may be NULL, e.g.
 * if mapping anonymous memory.
 * @file contains the file structure for file to map (may be NULL).
 * @reqprot contains the protection requested by the application.
 * @prot contains the protection that will be applied by the kernel.
 * @flags contains the operational flags.
 * Return 0 if permission is granted.
 */
1483
static int smack_mmap_file(struct file *file,
1484
			   unsigned long reqprot, unsigned long prot,
1485
			   unsigned long flags)
1486
{
1487
	struct smack_known *skp;
1488
	struct smack_known *mkp;
1489 1490
	struct smack_rule *srp;
	struct task_smack *tsp;
1491
	struct smack_known *okp;
1492
	struct inode_smack *isp;
1493 1494 1495
	int may;
	int mmay;
	int tmay;
1496 1497
	int rc;

A
Al Viro 已提交
1498
	if (file == NULL)
1499 1500
		return 0;

A
Al Viro 已提交
1501
	isp = file_inode(file)->i_security;
1502 1503
	if (isp->smk_mmap == NULL)
		return 0;
1504
	mkp = isp->smk_mmap;
1505 1506

	tsp = current_security();
1507
	skp = smk_of_current();
1508 1509 1510 1511 1512 1513 1514 1515
	rc = 0;

	rcu_read_lock();
	/*
	 * For each Smack rule associated with the subject
	 * label verify that the SMACK64MMAP also has access
	 * to that rule's object label.
	 */
1516
	list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1517
		okp = srp->smk_object;
1518 1519 1520
		/*
		 * Matching labels always allows access.
		 */
1521
		if (mkp->smk_known == okp->smk_known)
1522
			continue;
1523 1524 1525 1526
		/*
		 * If there is a matching local rule take
		 * that into account as well.
		 */
1527 1528 1529
		may = smk_access_entry(srp->smk_subject->smk_known,
				       okp->smk_known,
				       &tsp->smk_rules);
1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545
		if (may == -ENOENT)
			may = srp->smk_access;
		else
			may &= srp->smk_access;
		/*
		 * If may is zero the SMACK64MMAP subject can't
		 * possibly have less access.
		 */
		if (may == 0)
			continue;

		/*
		 * Fetch the global list entry.
		 * If there isn't one a SMACK64MMAP subject
		 * can't have as much access as current.
		 */
1546 1547
		mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
					&mkp->smk_rules);
1548 1549 1550 1551 1552 1553 1554 1555
		if (mmay == -ENOENT) {
			rc = -EACCES;
			break;
		}
		/*
		 * If there is a local entry it modifies the
		 * potential access, too.
		 */
1556 1557
		tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
					&tsp->smk_rules);
1558 1559
		if (tmay != -ENOENT)
			mmay &= tmay;
1560

1561 1562 1563 1564 1565
		/*
		 * If there is any access available to current that is
		 * not available to a SMACK64MMAP subject
		 * deny access.
		 */
1566
		if ((may | mmay) != mmay) {
1567
			rc = -EACCES;
1568
			break;
1569
		}
1570 1571 1572 1573 1574 1575 1576
	}

	rcu_read_unlock();

	return rc;
}

1577 1578 1579 1580 1581
/**
 * smack_file_set_fowner - set the file security blob value
 * @file: object in question
 *
 */
1582
static void smack_file_set_fowner(struct file *file)
1583
{
C
Casey Schaufler 已提交
1584
	file->f_security = smk_of_current();
1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600
}

/**
 * smack_file_send_sigiotask - Smack on sigio
 * @tsk: The target task
 * @fown: the object the signal come from
 * @signum: unused
 *
 * Allow a privileged task to get signals even if it shouldn't
 *
 * Returns 0 if a subject with the object's smack could
 * write to the task, an error code otherwise.
 */
static int smack_file_send_sigiotask(struct task_struct *tsk,
				     struct fown_struct *fown, int signum)
{
1601 1602
	struct smack_known *skp;
	struct smack_known *tkp = smk_of_task(tsk->cred->security);
1603 1604
	struct file *file;
	int rc;
E
Etienne Basset 已提交
1605
	struct smk_audit_info ad;
1606 1607 1608 1609 1610

	/*
	 * struct fown_struct is never outside the context of a struct file
	 */
	file = container_of(fown, struct file, f_owner);
1611

E
Etienne Basset 已提交
1612
	/* we don't log here as rc can be overriden */
1613 1614 1615
	skp = file->f_security;
	rc = smk_access(skp, tkp, MAY_WRITE, NULL);
	rc = smk_bu_note("sigiotask", skp, tkp, MAY_WRITE, rc);
1616
	if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
E
Etienne Basset 已提交
1617 1618 1619 1620
		rc = 0;

	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
	smk_ad_setfield_u_tsk(&ad, tsk);
1621
	smack_log(skp->smk_known, tkp->smk_known, MAY_WRITE, rc, &ad);
1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632
	return rc;
}

/**
 * smack_file_receive - Smack file receive check
 * @file: the object
 *
 * Returns 0 if current has access, error code otherwise
 */
static int smack_file_receive(struct file *file)
{
C
Casey Schaufler 已提交
1633
	int rc;
1634
	int may = 0;
E
Etienne Basset 已提交
1635
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1636
	struct inode *inode = file_inode(file);
1637

1638
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
E
Etienne Basset 已提交
1639
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1640 1641 1642 1643 1644 1645 1646 1647
	/*
	 * This code relies on bitmasks.
	 */
	if (file->f_mode & FMODE_READ)
		may = MAY_READ;
	if (file->f_mode & FMODE_WRITE)
		may |= MAY_WRITE;

C
Casey Schaufler 已提交
1648
	rc = smk_curacc(smk_of_inode(inode), may, &ad);
C
Casey Schaufler 已提交
1649 1650
	rc = smk_bu_file(file, may, rc);
	return rc;
1651 1652
}

1653
/**
1654
 * smack_file_open - Smack dentry open processing
1655
 * @file: the object
1656
 * @cred: task credential
1657 1658
 *
 * Set the security blob in the file structure.
1659 1660 1661
 * Allow the open only if the task has read access. There are
 * many read operations (e.g. fstat) that you can do with an
 * fd even if you have the file open write-only.
1662 1663 1664
 *
 * Returns 0
 */
1665
static int smack_file_open(struct file *file, const struct cred *cred)
1666
{
1667
	struct task_smack *tsp = cred->security;
C
Casey Schaufler 已提交
1668
	struct inode *inode = file_inode(file);
1669 1670
	struct smk_audit_info ad;
	int rc;
1671

C
Casey Schaufler 已提交
1672
	if (smack_privileged(CAP_MAC_OVERRIDE))
1673
		return 0;
1674

1675 1676
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
C
Casey Schaufler 已提交
1677
	rc = smk_access(tsp->smk_task, smk_of_inode(inode), MAY_READ, &ad);
C
Casey Schaufler 已提交
1678
	rc = smk_bu_credfile(cred, file, MAY_READ, rc);
1679 1680

	return rc;
1681 1682
}

1683 1684 1685 1686
/*
 * Task hooks
 */

1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697
/**
 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
 * @new: the new credentials
 * @gfp: the atomicity of any memory allocations
 *
 * Prepare a blank set of credentials for modification.  This must allocate all
 * the memory the LSM module might require such that cred_transfer() can
 * complete without error.
 */
static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
1698 1699 1700 1701
	struct task_smack *tsp;

	tsp = new_task_smack(NULL, NULL, gfp);
	if (tsp == NULL)
1702
		return -ENOMEM;
1703 1704 1705

	cred->security = tsp;

1706 1707 1708 1709
	return 0;
}


1710
/**
1711 1712
 * smack_cred_free - "free" task-level security credentials
 * @cred: the credentials in question
1713 1714
 *
 */
1715
static void smack_cred_free(struct cred *cred)
1716
{
1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731
	struct task_smack *tsp = cred->security;
	struct smack_rule *rp;
	struct list_head *l;
	struct list_head *n;

	if (tsp == NULL)
		return;
	cred->security = NULL;

	list_for_each_safe(l, n, &tsp->smk_rules) {
		rp = list_entry(l, struct smack_rule, list);
		list_del(&rp->list);
		kfree(rp);
	}
	kfree(tsp);
1732 1733
}

D
David Howells 已提交
1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744
/**
 * smack_cred_prepare - prepare new set of credentials for modification
 * @new: the new credentials
 * @old: the original credentials
 * @gfp: the atomicity of any memory allocations
 *
 * Prepare a new set of credentials for modification.
 */
static int smack_cred_prepare(struct cred *new, const struct cred *old,
			      gfp_t gfp)
{
1745 1746
	struct task_smack *old_tsp = old->security;
	struct task_smack *new_tsp;
1747
	int rc;
1748

1749
	new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1750 1751 1752
	if (new_tsp == NULL)
		return -ENOMEM;

1753 1754 1755 1756
	rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
	if (rc != 0)
		return rc;

1757
	new->security = new_tsp;
D
David Howells 已提交
1758 1759 1760
	return 0;
}

1761 1762 1763 1764 1765 1766 1767 1768 1769
/**
 * smack_cred_transfer - Transfer the old credentials to the new credentials
 * @new: the new credentials
 * @old: the original credentials
 *
 * Fill in a set of blank credentials from another set of credentials.
 */
static void smack_cred_transfer(struct cred *new, const struct cred *old)
{
1770 1771 1772 1773 1774
	struct task_smack *old_tsp = old->security;
	struct task_smack *new_tsp = new->security;

	new_tsp->smk_task = old_tsp->smk_task;
	new_tsp->smk_forked = old_tsp->smk_task;
1775 1776 1777 1778 1779
	mutex_init(&new_tsp->smk_rules_lock);
	INIT_LIST_HEAD(&new_tsp->smk_rules);


	/* cbs copy rule list */
1780 1781
}

1782 1783
/**
 * smack_kernel_act_as - Set the subjective context in a set of credentials
1784 1785
 * @new: points to the set of credentials to be modified.
 * @secid: specifies the security ID to be set
1786 1787 1788 1789 1790
 *
 * Set the security data for a kernel service.
 */
static int smack_kernel_act_as(struct cred *new, u32 secid)
{
1791
	struct task_smack *new_tsp = new->security;
1792
	struct smack_known *skp = smack_from_secid(secid);
1793

1794
	if (skp == NULL)
1795 1796
		return -EINVAL;

1797
	new_tsp->smk_task = skp;
1798 1799 1800 1801 1802
	return 0;
}

/**
 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1803 1804
 * @new: points to the set of credentials to be modified
 * @inode: points to the inode to use as a reference
1805 1806 1807 1808 1809 1810 1811 1812
 *
 * Set the file creation context in a set of credentials to the same
 * as the objective context of the specified inode
 */
static int smack_kernel_create_files_as(struct cred *new,
					struct inode *inode)
{
	struct inode_smack *isp = inode->i_security;
1813
	struct task_smack *tsp = new->security;
1814

1815
	tsp->smk_forked = isp->smk_inode;
1816
	tsp->smk_task = tsp->smk_forked;
1817 1818 1819
	return 0;
}

E
Etienne Basset 已提交
1820 1821 1822
/**
 * smk_curacc_on_task - helper to log task related access
 * @p: the task object
1823 1824
 * @access: the access requested
 * @caller: name of the calling function for audit
E
Etienne Basset 已提交
1825 1826 1827
 *
 * Return 0 if access is permitted
 */
1828 1829
static int smk_curacc_on_task(struct task_struct *p, int access,
				const char *caller)
E
Etienne Basset 已提交
1830 1831
{
	struct smk_audit_info ad;
1832
	struct smack_known *skp = smk_of_task_struct(p);
C
Casey Schaufler 已提交
1833
	int rc;
E
Etienne Basset 已提交
1834

1835
	smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
E
Etienne Basset 已提交
1836
	smk_ad_setfield_u_tsk(&ad, p);
1837
	rc = smk_curacc(skp, access, &ad);
C
Casey Schaufler 已提交
1838 1839
	rc = smk_bu_task(p, access, rc);
	return rc;
E
Etienne Basset 已提交
1840 1841
}

1842 1843 1844 1845 1846 1847 1848 1849 1850
/**
 * smack_task_setpgid - Smack check on setting pgid
 * @p: the task object
 * @pgid: unused
 *
 * Return 0 if write access is permitted
 */
static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
{
1851
	return smk_curacc_on_task(p, MAY_WRITE, __func__);
1852 1853 1854 1855 1856 1857 1858 1859 1860 1861
}

/**
 * smack_task_getpgid - Smack access check for getpgid
 * @p: the object task
 *
 * Returns 0 if current can read the object task, error code otherwise
 */
static int smack_task_getpgid(struct task_struct *p)
{
1862
	return smk_curacc_on_task(p, MAY_READ, __func__);
1863 1864 1865 1866 1867 1868 1869 1870 1871 1872
}

/**
 * smack_task_getsid - Smack access check for getsid
 * @p: the object task
 *
 * Returns 0 if current can read the object task, error code otherwise
 */
static int smack_task_getsid(struct task_struct *p)
{
1873
	return smk_curacc_on_task(p, MAY_READ, __func__);
1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884
}

/**
 * smack_task_getsecid - get the secid of the task
 * @p: the object task
 * @secid: where to put the result
 *
 * Sets the secid to contain a u32 version of the smack label.
 */
static void smack_task_getsecid(struct task_struct *p, u32 *secid)
{
1885
	struct smack_known *skp = smk_of_task_struct(p);
1886 1887

	*secid = skp->smk_secid;
1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898
}

/**
 * smack_task_setnice - Smack check on setting nice
 * @p: the task object
 * @nice: unused
 *
 * Return 0 if write access is permitted
 */
static int smack_task_setnice(struct task_struct *p, int nice)
{
1899 1900 1901 1902
	int rc;

	rc = cap_task_setnice(p, nice);
	if (rc == 0)
1903
		rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1904
	return rc;
1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915
}

/**
 * smack_task_setioprio - Smack check on setting ioprio
 * @p: the task object
 * @ioprio: unused
 *
 * Return 0 if write access is permitted
 */
static int smack_task_setioprio(struct task_struct *p, int ioprio)
{
1916 1917 1918 1919
	int rc;

	rc = cap_task_setioprio(p, ioprio);
	if (rc == 0)
1920
		rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1921
	return rc;
1922 1923 1924 1925 1926 1927 1928 1929 1930 1931
}

/**
 * smack_task_getioprio - Smack check on reading ioprio
 * @p: the task object
 *
 * Return 0 if read access is permitted
 */
static int smack_task_getioprio(struct task_struct *p)
{
1932
	return smk_curacc_on_task(p, MAY_READ, __func__);
1933 1934 1935 1936 1937 1938 1939 1940 1941 1942
}

/**
 * smack_task_setscheduler - Smack check on setting scheduler
 * @p: the task object
 * @policy: unused
 * @lp: unused
 *
 * Return 0 if read access is permitted
 */
1943
static int smack_task_setscheduler(struct task_struct *p)
1944
{
1945 1946
	int rc;

1947
	rc = cap_task_setscheduler(p);
1948
	if (rc == 0)
1949
		rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1950
	return rc;
1951 1952 1953 1954 1955 1956 1957 1958 1959 1960
}

/**
 * smack_task_getscheduler - Smack check on reading scheduler
 * @p: the task object
 *
 * Return 0 if read access is permitted
 */
static int smack_task_getscheduler(struct task_struct *p)
{
1961
	return smk_curacc_on_task(p, MAY_READ, __func__);
1962 1963 1964 1965 1966 1967 1968 1969 1970 1971
}

/**
 * smack_task_movememory - Smack check on moving memory
 * @p: the task object
 *
 * Return 0 if write access is permitted
 */
static int smack_task_movememory(struct task_struct *p)
{
1972
	return smk_curacc_on_task(p, MAY_WRITE, __func__);
1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989
}

/**
 * smack_task_kill - Smack check on signal delivery
 * @p: the task object
 * @info: unused
 * @sig: unused
 * @secid: identifies the smack to use in lieu of current's
 *
 * Return 0 if write access is permitted
 *
 * The secid behavior is an artifact of an SELinux hack
 * in the USB code. Someday it may go away.
 */
static int smack_task_kill(struct task_struct *p, struct siginfo *info,
			   int sig, u32 secid)
{
E
Etienne Basset 已提交
1990
	struct smk_audit_info ad;
1991
	struct smack_known *skp;
1992
	struct smack_known *tkp = smk_of_task_struct(p);
C
Casey Schaufler 已提交
1993
	int rc;
E
Etienne Basset 已提交
1994 1995 1996

	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
	smk_ad_setfield_u_tsk(&ad, p);
1997 1998 1999 2000
	/*
	 * Sending a signal requires that the sender
	 * can write the receiver.
	 */
C
Casey Schaufler 已提交
2001
	if (secid == 0) {
2002
		rc = smk_curacc(tkp, MAY_WRITE, &ad);
C
Casey Schaufler 已提交
2003 2004 2005
		rc = smk_bu_task(p, MAY_WRITE, rc);
		return rc;
	}
2006 2007 2008 2009 2010
	/*
	 * If the secid isn't 0 we're dealing with some USB IO
	 * specific behavior. This is not clean. For one thing
	 * we can't take privilege into account.
	 */
2011
	skp = smack_from_secid(secid);
2012 2013
	rc = smk_access(skp, tkp, MAY_WRITE, &ad);
	rc = smk_bu_note("USB signal", skp, tkp, MAY_WRITE, rc);
C
Casey Schaufler 已提交
2014
	return rc;
2015 2016 2017 2018 2019 2020
}

/**
 * smack_task_wait - Smack access check for waiting
 * @p: task to wait for
 *
2021
 * Returns 0
2022 2023 2024 2025
 */
static int smack_task_wait(struct task_struct *p)
{
	/*
2026 2027 2028 2029 2030 2031
	 * Allow the operation to succeed.
	 * Zombies are bad.
	 * In userless environments (e.g. phones) programs
	 * get marked with SMACK64EXEC and even if the parent
	 * and child shouldn't be talking the parent still
	 * may expect to know when the child exits.
2032
	 */
2033
	return 0;
2034 2035 2036 2037 2038
}

/**
 * smack_task_to_inode - copy task smack into the inode blob
 * @p: task to copy from
2039
 * @inode: inode to copy to
2040 2041 2042 2043 2044 2045
 *
 * Sets the smack pointer in the inode security blob
 */
static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
{
	struct inode_smack *isp = inode->i_security;
2046
	struct smack_known *skp = smk_of_task_struct(p);
2047

2048
	isp->smk_inode = skp;
2049 2050 2051 2052 2053 2054 2055 2056 2057 2058
}

/*
 * Socket hooks.
 */

/**
 * smack_sk_alloc_security - Allocate a socket blob
 * @sk: the socket
 * @family: unused
2059
 * @gfp_flags: memory allocation flags
2060 2061 2062 2063 2064 2065 2066
 *
 * Assign Smack pointers to current
 *
 * Returns 0 on success, -ENOMEM is there's no memory
 */
static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
{
2067
	struct smack_known *skp = smk_of_current();
2068 2069 2070 2071 2072 2073
	struct socket_smack *ssp;

	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
	if (ssp == NULL)
		return -ENOMEM;

2074
	ssp->smk_in = skp;
2075
	ssp->smk_out = skp;
2076
	ssp->smk_packet = NULL;
2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093

	sk->sk_security = ssp;

	return 0;
}

/**
 * smack_sk_free_security - Free a socket blob
 * @sk: the socket
 *
 * Clears the blob pointer
 */
static void smack_sk_free_security(struct sock *sk)
{
	kfree(sk->sk_security);
}

2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105
/**
* smack_host_label - check host based restrictions
* @sip: the object end
*
* looks for host based access restrictions
*
* This version will only be appropriate for really small sets of single label
* hosts.  The caller is responsible for ensuring that the RCU read lock is
* taken before calling this function.
*
* Returns the label of the far end or NULL if it's not special.
*/
2106
static struct smack_known *smack_host_label(struct sockaddr_in *sip)
2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120
{
	struct smk_netlbladdr *snp;
	struct in_addr *siap = &sip->sin_addr;

	if (siap->s_addr == 0)
		return NULL;

	list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
		/*
		* we break after finding the first match because
		* the list is sorted from longest to shortest mask
		* so we have found the most specific match
		*/
		if ((&snp->smk_host.sin_addr)->s_addr ==
2121 2122
		    (siap->s_addr & (&snp->smk_mask)->s_addr)) {
			/* we have found the special CIPSO option */
2123
			if (snp->smk_label == &smack_cipso_option)
2124
				return NULL;
2125
			return snp->smk_label;
2126
		}
2127 2128 2129 2130

	return NULL;
}

2131 2132 2133
/**
 * smack_netlabel - Set the secattr on a socket
 * @sk: the socket
2134
 * @labeled: socket label scheme
2135 2136 2137 2138 2139 2140
 *
 * Convert the outbound smack value (smk_out) to a
 * secattr and attach it to the socket.
 *
 * Returns 0 on success or an error code
 */
2141
static int smack_netlabel(struct sock *sk, int labeled)
2142
{
2143
	struct smack_known *skp;
2144
	struct socket_smack *ssp = sk->sk_security;
2145
	int rc = 0;
2146

2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161
	/*
	 * Usually the netlabel code will handle changing the
	 * packet labeling based on the label.
	 * The case of a single label host is different, because
	 * a single label host should never get a labeled packet
	 * even though the label is usually associated with a packet
	 * label.
	 */
	local_bh_disable();
	bh_lock_sock_nested(sk);

	if (ssp->smk_out == smack_net_ambient ||
	    labeled == SMACK_UNLABELED_SOCKET)
		netlbl_sock_delattr(sk);
	else {
2162
		skp = ssp->smk_out;
2163
		rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
2164 2165 2166 2167
	}

	bh_unlock_sock(sk);
	local_bh_enable();
2168

2169 2170 2171
	return rc;
}

2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184
/**
 * smack_netlbel_send - Set the secattr on a socket and perform access checks
 * @sk: the socket
 * @sap: the destination address
 *
 * Set the correct secattr for the given socket based on the destination
 * address and perform any outbound access checks needed.
 *
 * Returns 0 on success or an error code.
 *
 */
static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
{
2185
	struct smack_known *skp;
2186 2187
	int rc;
	int sk_lbl;
2188
	struct smack_known *hkp;
2189
	struct socket_smack *ssp = sk->sk_security;
E
Etienne Basset 已提交
2190
	struct smk_audit_info ad;
2191 2192

	rcu_read_lock();
2193 2194
	hkp = smack_host_label(sap);
	if (hkp != NULL) {
E
Etienne Basset 已提交
2195
#ifdef CONFIG_AUDIT
2196 2197
		struct lsm_network_audit net;

2198 2199 2200 2201
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
		ad.a.u.net->family = sap->sin_family;
		ad.a.u.net->dport = sap->sin_port;
		ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
E
Etienne Basset 已提交
2202
#endif
2203
		sk_lbl = SMACK_UNLABELED_SOCKET;
2204
		skp = ssp->smk_out;
2205 2206
		rc = smk_access(skp, hkp, MAY_WRITE, &ad);
		rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217
	} else {
		sk_lbl = SMACK_CIPSO_SOCKET;
		rc = 0;
	}
	rcu_read_unlock();
	if (rc != 0)
		return rc;

	return smack_netlabel(sk, sk_lbl);
}

2218
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298
/**
 * smk_ipv6_port_label - Smack port access table management
 * @sock: socket
 * @address: address
 *
 * Create or update the port list entry
 */
static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
{
	struct sock *sk = sock->sk;
	struct sockaddr_in6 *addr6;
	struct socket_smack *ssp = sock->sk->sk_security;
	struct smk_port_label *spp;
	unsigned short port = 0;

	if (address == NULL) {
		/*
		 * This operation is changing the Smack information
		 * on the bound socket. Take the changes to the port
		 * as well.
		 */
		list_for_each_entry(spp, &smk_ipv6_port_list, list) {
			if (sk != spp->smk_sock)
				continue;
			spp->smk_in = ssp->smk_in;
			spp->smk_out = ssp->smk_out;
			return;
		}
		/*
		 * A NULL address is only used for updating existing
		 * bound entries. If there isn't one, it's OK.
		 */
		return;
	}

	addr6 = (struct sockaddr_in6 *)address;
	port = ntohs(addr6->sin6_port);
	/*
	 * This is a special case that is safely ignored.
	 */
	if (port == 0)
		return;

	/*
	 * Look for an existing port list entry.
	 * This is an indication that a port is getting reused.
	 */
	list_for_each_entry(spp, &smk_ipv6_port_list, list) {
		if (spp->smk_port != port)
			continue;
		spp->smk_port = port;
		spp->smk_sock = sk;
		spp->smk_in = ssp->smk_in;
		spp->smk_out = ssp->smk_out;
		return;
	}

	/*
	 * A new port entry is required.
	 */
	spp = kzalloc(sizeof(*spp), GFP_KERNEL);
	if (spp == NULL)
		return;

	spp->smk_port = port;
	spp->smk_sock = sk;
	spp->smk_in = ssp->smk_in;
	spp->smk_out = ssp->smk_out;

	list_add(&spp->list, &smk_ipv6_port_list);
	return;
}

/**
 * smk_ipv6_port_check - check Smack port access
 * @sock: socket
 * @address: address
 *
 * Create or update the port list entry
 */
2299
static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
2300 2301 2302 2303 2304 2305
				int act)
{
	__be16 *bep;
	__be32 *be32p;
	struct smk_port_label *spp;
	struct socket_smack *ssp = sk->sk_security;
2306
	struct smack_known *skp;
2307
	unsigned short port = 0;
2308
	struct smack_known *object;
2309
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2310
	int rc;
2311 2312 2313 2314 2315
#ifdef CONFIG_AUDIT
	struct lsm_network_audit net;
#endif

	if (act == SMK_RECEIVING) {
2316
		skp = smack_net_ambient;
2317
		object = ssp->smk_in;
2318
	} else {
2319
		skp = ssp->smk_out;
2320
		object = smack_net_ambient;
2321 2322 2323 2324 2325
	}

	/*
	 * Get the IP address and port from the address.
	 */
2326 2327 2328
	port = ntohs(address->sin6_port);
	bep = (__be16 *)(&address->sin6_addr);
	be32p = (__be32 *)(&address->sin6_addr);
2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339

	/*
	 * It's remote, so port lookup does no good.
	 */
	if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1)
		goto auditout;

	/*
	 * It's local so the send check has to have passed.
	 */
	if (act == SMK_RECEIVING) {
2340
		skp = &smack_known_web;
2341 2342 2343 2344 2345 2346
		goto auditout;
	}

	list_for_each_entry(spp, &smk_ipv6_port_list, list) {
		if (spp->smk_port != port)
			continue;
2347
		object = spp->smk_in;
2348
		if (act == SMK_CONNECTING)
2349
			ssp->smk_packet = spp->smk_out;
2350 2351 2352 2353 2354 2355 2356 2357 2358 2359
		break;
	}

auditout:

#ifdef CONFIG_AUDIT
	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
	ad.a.u.net->family = sk->sk_family;
	ad.a.u.net->dport = port;
	if (act == SMK_RECEIVING)
2360
		ad.a.u.net->v6info.saddr = address->sin6_addr;
2361
	else
2362
		ad.a.u.net->v6info.daddr = address->sin6_addr;
2363
#endif
C
Casey Schaufler 已提交
2364 2365 2366
	rc = smk_access(skp, object, MAY_WRITE, &ad);
	rc = smk_bu_note("IPv6 port check", skp, object, MAY_WRITE, rc);
	return rc;
2367
}
2368
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
2369

2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384
/**
 * smack_inode_setsecurity - set smack xattrs
 * @inode: the object
 * @name: attribute name
 * @value: attribute value
 * @size: size of the attribute
 * @flags: unused
 *
 * Sets the named attribute in the appropriate blob
 *
 * Returns 0 on success, or an error code
 */
static int smack_inode_setsecurity(struct inode *inode, const char *name,
				   const void *value, size_t size, int flags)
{
2385
	struct smack_known *skp;
2386 2387 2388
	struct inode_smack *nsp = inode->i_security;
	struct socket_smack *ssp;
	struct socket *sock;
2389
	int rc = 0;
2390

2391
	if (value == NULL || size > SMK_LONGLABEL || size == 0)
P
Pankaj Kumar 已提交
2392
		return -EINVAL;
2393

2394 2395
	skp = smk_import_entry(value, size);
	if (skp == NULL)
2396 2397 2398
		return -EINVAL;

	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2399
		nsp->smk_inode = skp;
2400
		nsp->smk_flags |= SMK_INODE_INSTANT;
2401 2402 2403 2404 2405 2406 2407 2408 2409
		return 0;
	}
	/*
	 * The rest of the Smack xattrs are only on sockets.
	 */
	if (inode->i_sb->s_magic != SOCKFS_MAGIC)
		return -EOPNOTSUPP;

	sock = SOCKET_I(inode);
2410
	if (sock == NULL || sock->sk == NULL)
2411 2412 2413 2414 2415
		return -EOPNOTSUPP;

	ssp = sock->sk->sk_security;

	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2416
		ssp->smk_in = skp;
2417
	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2418
		ssp->smk_out = skp;
2419
		if (sock->sk->sk_family == PF_INET) {
C
Casey Schaufler 已提交
2420 2421 2422 2423 2424 2425
			rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
			if (rc != 0)
				printk(KERN_WARNING
					"Smack: \"%s\" netlbl error %d.\n",
					__func__, -rc);
		}
2426 2427 2428
	} else
		return -EOPNOTSUPP;

2429
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
2430 2431
	if (sock->sk->sk_family == PF_INET6)
		smk_ipv6_port_label(sock, NULL);
2432
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
2433

2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451
	return 0;
}

/**
 * smack_socket_post_create - finish socket setup
 * @sock: the socket
 * @family: protocol family
 * @type: unused
 * @protocol: unused
 * @kern: unused
 *
 * Sets the netlabel information on the socket
 *
 * Returns 0 on success, and error code otherwise
 */
static int smack_socket_post_create(struct socket *sock, int family,
				    int type, int protocol, int kern)
{
2452
	if (family != PF_INET || sock->sk == NULL)
2453 2454 2455 2456
		return 0;
	/*
	 * Set the outbound netlbl.
	 */
2457 2458 2459
	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
}

2460
#ifndef CONFIG_SECURITY_SMACK_NETFILTER
2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473
/**
 * smack_socket_bind - record port binding information.
 * @sock: the socket
 * @address: the port address
 * @addrlen: size of the address
 *
 * Records the label bound to a port.
 *
 * Returns 0
 */
static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
				int addrlen)
{
2474
#if IS_ENABLED(CONFIG_IPV6)
2475 2476
	if (sock->sk != NULL && sock->sk->sk_family == PF_INET6)
		smk_ipv6_port_label(sock, address);
2477
#endif
2478 2479 2480

	return 0;
}
2481
#endif /* !CONFIG_SECURITY_SMACK_NETFILTER */
2482

2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495
/**
 * smack_socket_connect - connect access check
 * @sock: the socket
 * @sap: the other end
 * @addrlen: size of sap
 *
 * Verifies that a connection may be possible
 *
 * Returns 0 on success, and error code otherwise
 */
static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
				int addrlen)
{
2496 2497 2498
	int rc = 0;

	if (sock->sk == NULL)
2499 2500
		return 0;

2501 2502 2503 2504 2505 2506 2507 2508 2509
	switch (sock->sk->sk_family) {
	case PF_INET:
		if (addrlen < sizeof(struct sockaddr_in))
			return -EINVAL;
		rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
		break;
	case PF_INET6:
		if (addrlen < sizeof(struct sockaddr_in6))
			return -EINVAL;
2510
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
2511 2512
		rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap,
						SMK_CONNECTING);
2513
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
2514 2515 2516
		break;
	}
	return rc;
2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546
}

/**
 * smack_flags_to_may - convert S_ to MAY_ values
 * @flags: the S_ value
 *
 * Returns the equivalent MAY_ value
 */
static int smack_flags_to_may(int flags)
{
	int may = 0;

	if (flags & S_IRUGO)
		may |= MAY_READ;
	if (flags & S_IWUGO)
		may |= MAY_WRITE;
	if (flags & S_IXUGO)
		may |= MAY_EXEC;

	return may;
}

/**
 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
 * @msg: the object
 *
 * Returns 0
 */
static int smack_msg_msg_alloc_security(struct msg_msg *msg)
{
2547 2548
	struct smack_known *skp = smk_of_current();

2549
	msg->security = skp;
2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569
	return 0;
}

/**
 * smack_msg_msg_free_security - Clear the security blob for msg_msg
 * @msg: the object
 *
 * Clears the blob pointer
 */
static void smack_msg_msg_free_security(struct msg_msg *msg)
{
	msg->security = NULL;
}

/**
 * smack_of_shm - the smack pointer for the shm
 * @shp: the object
 *
 * Returns a pointer to the smack value
 */
2570
static struct smack_known *smack_of_shm(struct shmid_kernel *shp)
2571
{
2572
	return (struct smack_known *)shp->shm_perm.security;
2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583
}

/**
 * smack_shm_alloc_security - Set the security blob for shm
 * @shp: the object
 *
 * Returns 0
 */
static int smack_shm_alloc_security(struct shmid_kernel *shp)
{
	struct kern_ipc_perm *isp = &shp->shm_perm;
2584
	struct smack_known *skp = smk_of_current();
2585

2586
	isp->security = skp;
2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602
	return 0;
}

/**
 * smack_shm_free_security - Clear the security blob for shm
 * @shp: the object
 *
 * Clears the blob pointer
 */
static void smack_shm_free_security(struct shmid_kernel *shp)
{
	struct kern_ipc_perm *isp = &shp->shm_perm;

	isp->security = NULL;
}

E
Etienne Basset 已提交
2603 2604 2605 2606 2607 2608 2609 2610 2611
/**
 * smk_curacc_shm : check if current has access on shm
 * @shp : the object
 * @access : access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smk_curacc_shm(struct shmid_kernel *shp, int access)
{
2612
	struct smack_known *ssp = smack_of_shm(shp);
E
Etienne Basset 已提交
2613
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2614
	int rc;
E
Etienne Basset 已提交
2615 2616 2617 2618 2619

#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
	ad.a.u.ipc_id = shp->shm_perm.id;
#endif
C
Casey Schaufler 已提交
2620 2621 2622
	rc = smk_curacc(ssp, access, &ad);
	rc = smk_bu_current("shm", ssp, access, rc);
	return rc;
E
Etienne Basset 已提交
2623 2624
}

2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636
/**
 * smack_shm_associate - Smack access check for shm
 * @shp: the object
 * @shmflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
{
	int may;

	may = smack_flags_to_may(shmflg);
E
Etienne Basset 已提交
2637
	return smk_curacc_shm(shp, may);
2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670
}

/**
 * smack_shm_shmctl - Smack access check for shm
 * @shp: the object
 * @cmd: what it wants to do
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
{
	int may;

	switch (cmd) {
	case IPC_STAT:
	case SHM_STAT:
		may = MAY_READ;
		break;
	case IPC_SET:
	case SHM_LOCK:
	case SHM_UNLOCK:
	case IPC_RMID:
		may = MAY_READWRITE;
		break;
	case IPC_INFO:
	case SHM_INFO:
		/*
		 * System level information.
		 */
		return 0;
	default:
		return -EINVAL;
	}
E
Etienne Basset 已提交
2671
	return smk_curacc_shm(shp, may);
2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687
}

/**
 * smack_shm_shmat - Smack access for shmat
 * @shp: the object
 * @shmaddr: unused
 * @shmflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
			   int shmflg)
{
	int may;

	may = smack_flags_to_may(shmflg);
E
Etienne Basset 已提交
2688
	return smk_curacc_shm(shp, may);
2689 2690 2691 2692 2693 2694 2695 2696
}

/**
 * smack_of_sem - the smack pointer for the sem
 * @sma: the object
 *
 * Returns a pointer to the smack value
 */
2697
static struct smack_known *smack_of_sem(struct sem_array *sma)
2698
{
2699
	return (struct smack_known *)sma->sem_perm.security;
2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710
}

/**
 * smack_sem_alloc_security - Set the security blob for sem
 * @sma: the object
 *
 * Returns 0
 */
static int smack_sem_alloc_security(struct sem_array *sma)
{
	struct kern_ipc_perm *isp = &sma->sem_perm;
2711
	struct smack_known *skp = smk_of_current();
2712

2713
	isp->security = skp;
2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729
	return 0;
}

/**
 * smack_sem_free_security - Clear the security blob for sem
 * @sma: the object
 *
 * Clears the blob pointer
 */
static void smack_sem_free_security(struct sem_array *sma)
{
	struct kern_ipc_perm *isp = &sma->sem_perm;

	isp->security = NULL;
}

E
Etienne Basset 已提交
2730 2731 2732 2733 2734 2735 2736 2737 2738
/**
 * smk_curacc_sem : check if current has access on sem
 * @sma : the object
 * @access : access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smk_curacc_sem(struct sem_array *sma, int access)
{
2739
	struct smack_known *ssp = smack_of_sem(sma);
E
Etienne Basset 已提交
2740
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2741
	int rc;
E
Etienne Basset 已提交
2742 2743 2744 2745 2746

#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
	ad.a.u.ipc_id = sma->sem_perm.id;
#endif
C
Casey Schaufler 已提交
2747 2748 2749
	rc = smk_curacc(ssp, access, &ad);
	rc = smk_bu_current("sem", ssp, access, rc);
	return rc;
E
Etienne Basset 已提交
2750 2751
}

2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763
/**
 * smack_sem_associate - Smack access check for sem
 * @sma: the object
 * @semflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_sem_associate(struct sem_array *sma, int semflg)
{
	int may;

	may = smack_flags_to_may(semflg);
E
Etienne Basset 已提交
2764
	return smk_curacc_sem(sma, may);
2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803
}

/**
 * smack_sem_shmctl - Smack access check for sem
 * @sma: the object
 * @cmd: what it wants to do
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_sem_semctl(struct sem_array *sma, int cmd)
{
	int may;

	switch (cmd) {
	case GETPID:
	case GETNCNT:
	case GETZCNT:
	case GETVAL:
	case GETALL:
	case IPC_STAT:
	case SEM_STAT:
		may = MAY_READ;
		break;
	case SETVAL:
	case SETALL:
	case IPC_RMID:
	case IPC_SET:
		may = MAY_READWRITE;
		break;
	case IPC_INFO:
	case SEM_INFO:
		/*
		 * System level information
		 */
		return 0;
	default:
		return -EINVAL;
	}

E
Etienne Basset 已提交
2804
	return smk_curacc_sem(sma, may);
2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820
}

/**
 * smack_sem_semop - Smack checks of semaphore operations
 * @sma: the object
 * @sops: unused
 * @nsops: unused
 * @alter: unused
 *
 * Treated as read and write in all cases.
 *
 * Returns 0 if access is allowed, error code otherwise
 */
static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
			   unsigned nsops, int alter)
{
E
Etienne Basset 已提交
2821
	return smk_curacc_sem(sma, MAY_READWRITE);
2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832
}

/**
 * smack_msg_alloc_security - Set the security blob for msg
 * @msq: the object
 *
 * Returns 0
 */
static int smack_msg_queue_alloc_security(struct msg_queue *msq)
{
	struct kern_ipc_perm *kisp = &msq->q_perm;
2833
	struct smack_known *skp = smk_of_current();
2834

2835
	kisp->security = skp;
2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855
	return 0;
}

/**
 * smack_msg_free_security - Clear the security blob for msg
 * @msq: the object
 *
 * Clears the blob pointer
 */
static void smack_msg_queue_free_security(struct msg_queue *msq)
{
	struct kern_ipc_perm *kisp = &msq->q_perm;

	kisp->security = NULL;
}

/**
 * smack_of_msq - the smack pointer for the msq
 * @msq: the object
 *
2856
 * Returns a pointer to the smack label entry
2857
 */
2858
static struct smack_known *smack_of_msq(struct msg_queue *msq)
2859
{
2860
	return (struct smack_known *)msq->q_perm.security;
2861 2862
}

E
Etienne Basset 已提交
2863 2864 2865 2866 2867 2868 2869 2870 2871
/**
 * smk_curacc_msq : helper to check if current has access on msq
 * @msq : the msq
 * @access : access requested
 *
 * return 0 if current has access, error otherwise
 */
static int smk_curacc_msq(struct msg_queue *msq, int access)
{
2872
	struct smack_known *msp = smack_of_msq(msq);
E
Etienne Basset 已提交
2873
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2874
	int rc;
E
Etienne Basset 已提交
2875 2876 2877 2878 2879

#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
	ad.a.u.ipc_id = msq->q_perm.id;
#endif
C
Casey Schaufler 已提交
2880 2881 2882
	rc = smk_curacc(msp, access, &ad);
	rc = smk_bu_current("msq", msp, access, rc);
	return rc;
E
Etienne Basset 已提交
2883 2884
}

2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896
/**
 * smack_msg_queue_associate - Smack access check for msg_queue
 * @msq: the object
 * @msqflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
{
	int may;

	may = smack_flags_to_may(msqflg);
E
Etienne Basset 已提交
2897
	return smk_curacc_msq(msq, may);
2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929
}

/**
 * smack_msg_queue_msgctl - Smack access check for msg_queue
 * @msq: the object
 * @cmd: what it wants to do
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
{
	int may;

	switch (cmd) {
	case IPC_STAT:
	case MSG_STAT:
		may = MAY_READ;
		break;
	case IPC_SET:
	case IPC_RMID:
		may = MAY_READWRITE;
		break;
	case IPC_INFO:
	case MSG_INFO:
		/*
		 * System level information
		 */
		return 0;
	default:
		return -EINVAL;
	}

E
Etienne Basset 已提交
2930
	return smk_curacc_msq(msq, may);
2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943
}

/**
 * smack_msg_queue_msgsnd - Smack access check for msg_queue
 * @msq: the object
 * @msg: unused
 * @msqflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
				  int msqflg)
{
E
Etienne Basset 已提交
2944
	int may;
2945

E
Etienne Basset 已提交
2946 2947
	may = smack_flags_to_may(msqflg);
	return smk_curacc_msq(msq, may);
2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962
}

/**
 * smack_msg_queue_msgsnd - Smack access check for msg_queue
 * @msq: the object
 * @msg: unused
 * @target: unused
 * @type: unused
 * @mode: unused
 *
 * Returns 0 if current has read and write access, error code otherwise
 */
static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
			struct task_struct *target, long type, int mode)
{
E
Etienne Basset 已提交
2963
	return smk_curacc_msq(msq, MAY_READWRITE);
2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974
}

/**
 * smack_ipc_permission - Smack access for ipc_permission()
 * @ipp: the object permissions
 * @flag: access requested
 *
 * Returns 0 if current has read and write access, error code otherwise
 */
static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
{
2975
	struct smack_known *iskp = ipp->security;
E
Etienne Basset 已提交
2976 2977
	int may = smack_flags_to_may(flag);
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2978
	int rc;
2979

E
Etienne Basset 已提交
2980 2981 2982 2983
#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
	ad.a.u.ipc_id = ipp->id;
#endif
2984 2985
	rc = smk_curacc(iskp, may, &ad);
	rc = smk_bu_current("svipc", iskp, may, rc);
C
Casey Schaufler 已提交
2986
	return rc;
2987 2988
}

2989 2990
/**
 * smack_ipc_getsecid - Extract smack security id
2991
 * @ipp: the object permissions
2992 2993 2994 2995
 * @secid: where result will be saved
 */
static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
{
2996
	struct smack_known *iskp = ipp->security;
2997

2998
	*secid = iskp->smk_secid;
2999 3000
}

3001 3002
/**
 * smack_d_instantiate - Make sure the blob is correct on an inode
3003
 * @opt_dentry: dentry where inode will be attached
3004 3005 3006 3007 3008 3009 3010 3011 3012
 * @inode: the object
 *
 * Set the inode's security blob if it hasn't been done already.
 */
static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
{
	struct super_block *sbp;
	struct superblock_smack *sbsp;
	struct inode_smack *isp;
3013 3014
	struct smack_known *skp;
	struct smack_known *ckp = smk_of_current();
3015
	struct smack_known *final;
3016 3017
	char trattr[TRANS_TRUE_SIZE];
	int transflag = 0;
C
Casey Schaufler 已提交
3018
	int rc;
3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041
	struct dentry *dp;

	if (inode == NULL)
		return;

	isp = inode->i_security;

	mutex_lock(&isp->smk_lock);
	/*
	 * If the inode is already instantiated
	 * take the quick way out
	 */
	if (isp->smk_flags & SMK_INODE_INSTANT)
		goto unlockandout;

	sbp = inode->i_sb;
	sbsp = sbp->s_security;
	/*
	 * We're going to use the superblock default label
	 * if there's no label on the file.
	 */
	final = sbsp->smk_default;

C
Casey Schaufler 已提交
3042 3043 3044 3045 3046 3047 3048
	/*
	 * If this is the root inode the superblock
	 * may be in the process of initialization.
	 * If that is the case use the root value out
	 * of the superblock.
	 */
	if (opt_dentry->d_parent == opt_dentry) {
3049 3050
		switch (sbp->s_magic) {
		case CGROUP_SUPER_MAGIC:
3051 3052 3053 3054 3055
			/*
			 * The cgroup filesystem is never mounted,
			 * so there's no opportunity to set the mount
			 * options.
			 */
3056 3057
			sbsp->smk_root = &smack_known_star;
			sbsp->smk_default = &smack_known_star;
3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069
			isp->smk_inode = sbsp->smk_root;
			break;
		case TMPFS_MAGIC:
			/*
			 * What about shmem/tmpfs anonymous files with dentry
			 * obtained from d_alloc_pseudo()?
			 */
			isp->smk_inode = smk_of_current();
			break;
		default:
			isp->smk_inode = sbsp->smk_root;
			break;
3070
		}
C
Casey Schaufler 已提交
3071 3072 3073 3074
		isp->smk_flags |= SMK_INODE_INSTANT;
		goto unlockandout;
	}

3075 3076 3077 3078 3079 3080 3081 3082
	/*
	 * This is pretty hackish.
	 * Casey says that we shouldn't have to do
	 * file system specific code, but it does help
	 * with keeping it simple.
	 */
	switch (sbp->s_magic) {
	case SMACK_MAGIC:
3083 3084 3085
	case PIPEFS_MAGIC:
	case SOCKFS_MAGIC:
	case CGROUP_SUPER_MAGIC:
3086
		/*
L
Lucas De Marchi 已提交
3087
		 * Casey says that it's a little embarrassing
3088 3089
		 * that the smack file system doesn't do
		 * extended attributes.
3090
		 *
3091
		 * Casey says pipes are easy (?)
3092 3093 3094 3095 3096
		 *
		 * Socket access is controlled by the socket
		 * structures associated with the task involved.
		 *
		 * Cgroupfs is special
3097
		 */
3098
		final = &smack_known_star;
3099 3100 3101 3102 3103 3104 3105
		break;
	case DEVPTS_SUPER_MAGIC:
		/*
		 * devpts seems content with the label of the task.
		 * Programs that change smack have to treat the
		 * pty with respect.
		 */
3106
		final = ckp;
3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119
		break;
	case PROC_SUPER_MAGIC:
		/*
		 * Casey says procfs appears not to care.
		 * The superblock default suffices.
		 */
		break;
	case TMPFS_MAGIC:
		/*
		 * Device labels should come from the filesystem,
		 * but watch out, because they're volitile,
		 * getting recreated on every reboot.
		 */
3120
		final = &smack_known_star;
3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132
		/*
		 * No break.
		 *
		 * If a smack value has been set we want to use it,
		 * but since tmpfs isn't giving us the opportunity
		 * to set mount options simulate setting the
		 * superblock default.
		 */
	default:
		/*
		 * This isn't an understood special case.
		 * Get the value from the xattr.
C
Casey Schaufler 已提交
3133 3134 3135 3136 3137 3138
		 */

		/*
		 * UNIX domain sockets use lower level socket data.
		 */
		if (S_ISSOCK(inode->i_mode)) {
3139
			final = &smack_known_star;
C
Casey Schaufler 已提交
3140 3141 3142
			break;
		}
		/*
3143 3144 3145 3146 3147 3148 3149 3150 3151 3152
		 * No xattr support means, alas, no SMACK label.
		 * Use the aforeapplied default.
		 * It would be curious if the label of the task
		 * does not match that assigned.
		 */
		if (inode->i_op->getxattr == NULL)
			break;
		/*
		 * Get the dentry for xattr.
		 */
3153
		dp = dget(opt_dentry);
3154 3155
		skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
		if (skp != NULL)
3156
			final = skp;
C
Casey Schaufler 已提交
3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173

		/*
		 * Transmuting directory
		 */
		if (S_ISDIR(inode->i_mode)) {
			/*
			 * If this is a new directory and the label was
			 * transmuted when the inode was initialized
			 * set the transmute attribute on the directory
			 * and mark the inode.
			 *
			 * If there is a transmute attribute on the
			 * directory mark the inode.
			 */
			if (isp->smk_flags & SMK_INODE_CHANGED) {
				isp->smk_flags &= ~SMK_INODE_CHANGED;
				rc = inode->i_op->setxattr(dp,
3174
					XATTR_NAME_SMACKTRANSMUTE,
C
Casey Schaufler 已提交
3175 3176 3177 3178 3179 3180 3181 3182 3183
					TRANS_TRUE, TRANS_TRUE_SIZE,
					0);
			} else {
				rc = inode->i_op->getxattr(dp,
					XATTR_NAME_SMACKTRANSMUTE, trattr,
					TRANS_TRUE_SIZE);
				if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
						       TRANS_TRUE_SIZE) != 0)
					rc = -EINVAL;
3184
			}
C
Casey Schaufler 已提交
3185 3186
			if (rc >= 0)
				transflag = SMK_INODE_TRANSMUTE;
3187
		}
3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198
		/*
		 * Don't let the exec or mmap label be "*" or "@".
		 */
		skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
		if (skp == &smack_known_star || skp == &smack_known_web)
			skp = NULL;
		isp->smk_task = skp;
		skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
		if (skp == &smack_known_star || skp == &smack_known_web)
			skp = NULL;
		isp->smk_mmap = skp;
3199

3200 3201 3202 3203 3204
		dput(dp);
		break;
	}

	if (final == NULL)
3205
		isp->smk_inode = ckp;
3206 3207 3208
	else
		isp->smk_inode = final;

3209
	isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227

unlockandout:
	mutex_unlock(&isp->smk_lock);
	return;
}

/**
 * smack_getprocattr - Smack process attribute access
 * @p: the object task
 * @name: the name of the attribute in /proc/.../attr
 * @value: where to put the result
 *
 * Places a copy of the task Smack into value
 *
 * Returns the length of the smack label or an error code
 */
static int smack_getprocattr(struct task_struct *p, char *name, char **value)
{
3228
	struct smack_known *skp = smk_of_task_struct(p);
3229 3230 3231 3232 3233 3234
	char *cp;
	int slen;

	if (strcmp(name, "current") != 0)
		return -EINVAL;

3235
	cp = kstrdup(skp->smk_known, GFP_KERNEL);
3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258
	if (cp == NULL)
		return -ENOMEM;

	slen = strlen(cp);
	*value = cp;
	return slen;
}

/**
 * smack_setprocattr - Smack process attribute setting
 * @p: the object task
 * @name: the name of the attribute in /proc/.../attr
 * @value: the value to set
 * @size: the size of the value
 *
 * Sets the Smack value of the task. Only setting self
 * is permitted and only with privilege
 *
 * Returns the length of the smack label or an error code
 */
static int smack_setprocattr(struct task_struct *p, char *name,
			     void *value, size_t size)
{
3259
	struct task_smack *tsp;
D
David Howells 已提交
3260
	struct cred *new;
3261
	struct smack_known *skp;
3262 3263 3264 3265 3266 3267 3268 3269

	/*
	 * Changing another process' Smack value is too dangerous
	 * and supports no sane use case.
	 */
	if (p != current)
		return -EPERM;

3270
	if (!smack_privileged(CAP_MAC_ADMIN))
3271 3272
		return -EPERM;

3273
	if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
3274 3275 3276 3277 3278
		return -EINVAL;

	if (strcmp(name, "current") != 0)
		return -EINVAL;

3279 3280
	skp = smk_import_entry(value, size);
	if (skp == NULL)
3281 3282
		return -EINVAL;

3283 3284 3285
	/*
	 * No process is ever allowed the web ("@") label.
	 */
3286
	if (skp == &smack_known_web)
3287 3288
		return -EPERM;

D
David Howells 已提交
3289
	new = prepare_creds();
3290
	if (new == NULL)
D
David Howells 已提交
3291
		return -ENOMEM;
3292

3293
	tsp = new->security;
3294
	tsp->smk_task = skp;
3295

D
David Howells 已提交
3296
	commit_creds(new);
3297 3298 3299 3300 3301
	return size;
}

/**
 * smack_unix_stream_connect - Smack access on UDS
3302 3303
 * @sock: one sock
 * @other: the other sock
3304 3305 3306 3307 3308
 * @newsk: unused
 *
 * Return 0 if a subject with the smack of sock could access
 * an object with the smack of other, otherwise an error code
 */
3309 3310
static int smack_unix_stream_connect(struct sock *sock,
				     struct sock *other, struct sock *newsk)
3311
{
3312
	struct smack_known *skp;
3313
	struct smack_known *okp;
J
James Morris 已提交
3314 3315
	struct socket_smack *ssp = sock->sk_security;
	struct socket_smack *osp = other->sk_security;
3316
	struct socket_smack *nsp = newsk->sk_security;
E
Etienne Basset 已提交
3317
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
3318
	int rc = 0;
3319 3320 3321
#ifdef CONFIG_AUDIT
	struct lsm_network_audit net;
#endif
C
Casey Schaufler 已提交
3322

3323 3324
	if (!smack_privileged(CAP_MAC_OVERRIDE)) {
		skp = ssp->smk_out;
3325
		okp = osp->smk_in;
3326 3327 3328 3329
#ifdef CONFIG_AUDIT
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
		smk_ad_setfield_u_net_sk(&ad, other);
#endif
3330 3331
		rc = smk_access(skp, okp, MAY_WRITE, &ad);
		rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc);
C
Casey Schaufler 已提交
3332
		if (rc == 0) {
3333 3334
			okp = osp->smk_out;
			skp = ssp->smk_in;
3335
			rc = smk_access(okp, skp, MAY_WRITE, &ad);
3336
			rc = smk_bu_note("UDS connect", okp, skp,
C
Casey Schaufler 已提交
3337 3338
						MAY_WRITE, rc);
		}
3339
	}
C
Casey Schaufler 已提交
3340

3341 3342 3343 3344
	/*
	 * Cross reference the peer labels for SO_PEERSEC.
	 */
	if (rc == 0) {
3345 3346
		nsp->smk_packet = ssp->smk_out;
		ssp->smk_packet = osp->smk_out;
3347 3348
	}

C
Casey Schaufler 已提交
3349
	return rc;
3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361
}

/**
 * smack_unix_may_send - Smack access on UDS
 * @sock: one socket
 * @other: the other socket
 *
 * Return 0 if a subject with the smack of sock could access
 * an object with the smack of other, otherwise an error code
 */
static int smack_unix_may_send(struct socket *sock, struct socket *other)
{
C
Casey Schaufler 已提交
3362 3363
	struct socket_smack *ssp = sock->sk->sk_security;
	struct socket_smack *osp = other->sk->sk_security;
E
Etienne Basset 已提交
3364
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
3365
	int rc;
3366

3367 3368 3369
#ifdef CONFIG_AUDIT
	struct lsm_network_audit net;

3370
	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
E
Etienne Basset 已提交
3371
	smk_ad_setfield_u_net_sk(&ad, other->sk);
3372
#endif
C
Casey Schaufler 已提交
3373

3374 3375
	if (smack_privileged(CAP_MAC_OVERRIDE))
		return 0;
C
Casey Schaufler 已提交
3376

3377 3378
	rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
	rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc);
C
Casey Schaufler 已提交
3379
	return rc;
3380 3381
}

3382 3383 3384
/**
 * smack_socket_sendmsg - Smack check based on destination host
 * @sock: the socket
3385
 * @msg: the message
3386 3387
 * @size: the size of the message
 *
3388 3389 3390
 * Return 0 if the current subject can write to the destination host.
 * For IPv4 this is only a question if the destination is a single label host.
 * For IPv6 this is a check against the label of the port.
3391 3392 3393 3394 3395
 */
static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
				int size)
{
	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
3396
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
3397
	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
3398
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
3399
	int rc = 0;
3400 3401 3402 3403

	/*
	 * Perfectly reasonable for this to be NULL
	 */
3404
	if (sip == NULL)
3405 3406
		return 0;

3407 3408 3409 3410 3411
	switch (sip->sin_family) {
	case AF_INET:
		rc = smack_netlabel_send(sock->sk, sip);
		break;
	case AF_INET6:
3412
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
3413
		rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
3414
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
3415 3416 3417
		break;
	}
	return rc;
3418 3419
}

3420
/**
3421
 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3422
 * @sap: netlabel secattr
3423
 * @ssp: socket security information
3424
 *
3425
 * Returns a pointer to a Smack label entry found on the label list.
3426
 */
3427 3428
static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
						struct socket_smack *ssp)
3429
{
3430
	struct smack_known *skp;
3431
	int found = 0;
C
Casey Schaufler 已提交
3432 3433
	int acat;
	int kcat;
3434

3435
	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3436
		/*
3437
		 * Looks like a CIPSO packet.
3438 3439 3440
		 * If there are flags but no level netlabel isn't
		 * behaving the way we expect it to.
		 *
3441
		 * Look it up in the label table
3442 3443 3444 3445
		 * Without guidance regarding the smack value
		 * for the packet fall back on the network
		 * ambient value.
		 */
3446
		rcu_read_lock();
3447 3448
		list_for_each_entry(skp, &smack_known_list, list) {
			if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3449
				continue;
C
Casey Schaufler 已提交
3450 3451 3452 3453 3454 3455 3456 3457 3458 3459
			/*
			 * Compare the catsets. Use the netlbl APIs.
			 */
			if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
				if ((skp->smk_netlabel.flags &
				     NETLBL_SECATTR_MLS_CAT) == 0)
					found = 1;
				break;
			}
			for (acat = -1, kcat = -1; acat == kcat; ) {
3460 3461 3462
				acat = netlbl_catmap_walk(sap->attr.mls.cat,
							  acat + 1);
				kcat = netlbl_catmap_walk(
C
Casey Schaufler 已提交
3463 3464 3465 3466 3467 3468 3469 3470 3471
					skp->smk_netlabel.attr.mls.cat,
					kcat + 1);
				if (acat < 0 || kcat < 0)
					break;
			}
			if (acat == kcat) {
				found = 1;
				break;
			}
3472
		}
3473 3474 3475
		rcu_read_unlock();

		if (found)
3476
			return skp;
3477

3478
		if (ssp != NULL && ssp->smk_in == &smack_known_star)
3479 3480
			return &smack_known_web;
		return &smack_known_star;
3481
	}
3482 3483 3484 3485
	if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
		/*
		 * Looks like a fallback, which gives us a secid.
		 */
3486
		skp = smack_from_secid(sap->attr.secid);
3487 3488 3489 3490 3491 3492 3493
		/*
		 * This has got to be a bug because it is
		 * impossible to specify a fallback without
		 * specifying the label, which will ensure
		 * it has a secid, and the only way to get a
		 * secid is from a fallback.
		 */
3494 3495
		BUG_ON(skp == NULL);
		return skp;
3496 3497
	}
	/*
3498 3499 3500
	 * Without guidance regarding the smack value
	 * for the packet fall back on the network
	 * ambient value.
3501
	 */
3502
	return smack_net_ambient;
3503 3504
}

3505
#if IS_ENABLED(CONFIG_IPV6)
3506
static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551
{
	u8 nexthdr;
	int offset;
	int proto = -EINVAL;
	struct ipv6hdr _ipv6h;
	struct ipv6hdr *ip6;
	__be16 frag_off;
	struct tcphdr _tcph, *th;
	struct udphdr _udph, *uh;
	struct dccp_hdr _dccph, *dh;

	sip->sin6_port = 0;

	offset = skb_network_offset(skb);
	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
	if (ip6 == NULL)
		return -EINVAL;
	sip->sin6_addr = ip6->saddr;

	nexthdr = ip6->nexthdr;
	offset += sizeof(_ipv6h);
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
	if (offset < 0)
		return -EINVAL;

	proto = nexthdr;
	switch (proto) {
	case IPPROTO_TCP:
		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
		if (th != NULL)
			sip->sin6_port = th->source;
		break;
	case IPPROTO_UDP:
		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
		if (uh != NULL)
			sip->sin6_port = uh->source;
		break;
	case IPPROTO_DCCP:
		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
		if (dh != NULL)
			sip->sin6_port = dh->dccph_sport;
		break;
	}
	return proto;
}
3552
#endif /* CONFIG_IPV6 */
3553

3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564
/**
 * smack_socket_sock_rcv_skb - Smack packet delivery access check
 * @sk: socket
 * @skb: packet
 *
 * Returns 0 if the packet should be delivered, an error code otherwise
 */
static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
	struct netlbl_lsm_secattr secattr;
	struct socket_smack *ssp = sk->sk_security;
3565
	struct smack_known *skp = NULL;
3566
	int rc = 0;
E
Etienne Basset 已提交
3567
	struct smk_audit_info ad;
3568
#ifdef CONFIG_AUDIT
3569
	struct lsm_network_audit net;
3570
#endif
3571 3572 3573 3574 3575
#if IS_ENABLED(CONFIG_IPV6)
	struct sockaddr_in6 sadd;
	int proto;
#endif /* CONFIG_IPV6 */

3576 3577
	switch (sk->sk_family) {
	case PF_INET:
3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
		/*
		 * If there is a secmark use it rather than the CIPSO label.
		 * If there is no secmark fall back to CIPSO.
		 * The secmark is assumed to reflect policy better.
		 */
		if (skb && skb->secmark != 0) {
			skp = smack_from_secid(skb->secmark);
			goto access_check;
		}
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
3589 3590 3591 3592
		/*
		 * Translate what netlabel gave us.
		 */
		netlbl_secattr_init(&secattr);
3593

3594 3595
		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
		if (rc == 0)
3596
			skp = smack_from_secattr(&secattr, ssp);
3597
		else
3598
			skp = smack_net_ambient;
3599

3600
		netlbl_secattr_destroy(&secattr);
3601

3602 3603 3604
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
access_check:
#endif
E
Etienne Basset 已提交
3605
#ifdef CONFIG_AUDIT
3606 3607 3608 3609
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
		ad.a.u.net->family = sk->sk_family;
		ad.a.u.net->netif = skb->skb_iif;
		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
E
Etienne Basset 已提交
3610
#endif
3611 3612 3613 3614 3615 3616
		/*
		 * Receiving a packet requires that the other end
		 * be able to write here. Read access is not required.
		 * This is the simplist possible security model
		 * for networking.
		 */
3617 3618
		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
C
Casey Schaufler 已提交
3619
					MAY_WRITE, rc);
3620 3621 3622
		if (rc != 0)
			netlbl_skbuff_err(skb, rc, 0);
		break;
3623
#if IS_ENABLED(CONFIG_IPV6)
3624
	case PF_INET6:
3625 3626 3627 3628 3629 3630
		proto = smk_skb_to_addr_ipv6(skb, &sadd);
		if (proto != IPPROTO_UDP && proto != IPPROTO_TCP)
			break;
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
		if (skb && skb->secmark != 0)
			skp = smack_from_secid(skb->secmark);
3631
		else
3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644
			skp = smack_net_ambient;
#ifdef CONFIG_AUDIT
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
		ad.a.u.net->family = sk->sk_family;
		ad.a.u.net->netif = skb->skb_iif;
		ipv6_skb_to_auditdata(skb, &ad.a, NULL);
#endif /* CONFIG_AUDIT */
		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
		rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
					MAY_WRITE, rc);
#else /* CONFIG_SECURITY_SMACK_NETFILTER */
		rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
3645
		break;
3646
#endif /* CONFIG_IPV6 */
3647
	}
3648

3649
	return rc;
3650 3651 3652 3653 3654 3655 3656
}

/**
 * smack_socket_getpeersec_stream - pull in packet label
 * @sock: the socket
 * @optval: user's destination
 * @optlen: size thereof
3657
 * @len: max thereof
3658 3659 3660 3661 3662 3663 3664 3665
 *
 * returns zero on success, an error code otherwise
 */
static int smack_socket_getpeersec_stream(struct socket *sock,
					  char __user *optval,
					  int __user *optlen, unsigned len)
{
	struct socket_smack *ssp;
3666 3667
	char *rcp = "";
	int slen = 1;
3668 3669 3670
	int rc = 0;

	ssp = sock->sk->sk_security;
3671
	if (ssp->smk_packet != NULL) {
3672
		rcp = ssp->smk_packet->smk_known;
3673 3674
		slen = strlen(rcp) + 1;
	}
3675 3676 3677

	if (slen > len)
		rc = -ERANGE;
3678
	else if (copy_to_user(optval, rcp, slen) != 0)
3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689
		rc = -EFAULT;

	if (put_user(slen, optlen) != 0)
		rc = -EFAULT;

	return rc;
}


/**
 * smack_socket_getpeersec_dgram - pull in packet label
C
Casey Schaufler 已提交
3690
 * @sock: the peer socket
3691 3692 3693 3694 3695 3696 3697 3698 3699 3700
 * @skb: packet data
 * @secid: pointer to where to put the secid of the packet
 *
 * Sets the netlabel socket state on sk from parent
 */
static int smack_socket_getpeersec_dgram(struct socket *sock,
					 struct sk_buff *skb, u32 *secid)

{
	struct netlbl_lsm_secattr secattr;
3701
	struct socket_smack *ssp = NULL;
3702
	struct smack_known *skp;
C
Casey Schaufler 已提交
3703 3704
	int family = PF_UNSPEC;
	u32 s = 0;	/* 0 is the invalid secid */
3705 3706
	int rc;

C
Casey Schaufler 已提交
3707 3708 3709
	if (skb != NULL) {
		if (skb->protocol == htons(ETH_P_IP))
			family = PF_INET;
3710
#if IS_ENABLED(CONFIG_IPV6)
C
Casey Schaufler 已提交
3711 3712
		else if (skb->protocol == htons(ETH_P_IPV6))
			family = PF_INET6;
3713
#endif /* CONFIG_IPV6 */
3714
	}
C
Casey Schaufler 已提交
3715 3716
	if (family == PF_UNSPEC && sock != NULL)
		family = sock->sk->sk_family;
3717

3718 3719
	switch (family) {
	case PF_UNIX:
3720
		ssp = sock->sk->sk_security;
3721
		s = ssp->smk_out->smk_secid;
3722 3723 3724 3725 3726 3727 3728
		break;
	case PF_INET:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
		s = skb->secmark;
		if (s != 0)
			break;
#endif
C
Casey Schaufler 已提交
3729 3730 3731
		/*
		 * Translate what netlabel gave us.
		 */
3732 3733
		if (sock != NULL && sock->sk != NULL)
			ssp = sock->sk->sk_security;
C
Casey Schaufler 已提交
3734 3735 3736
		netlbl_secattr_init(&secattr);
		rc = netlbl_skbuff_getattr(skb, family, &secattr);
		if (rc == 0) {
3737 3738
			skp = smack_from_secattr(&secattr, ssp);
			s = skp->smk_secid;
C
Casey Schaufler 已提交
3739 3740
		}
		netlbl_secattr_destroy(&secattr);
3741 3742 3743 3744 3745 3746 3747 3748
		break;
#if IS_ENABLED(CONFIG_IPV6)
	case PF_INET6:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
		s = skb->secmark;
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
		break;
#endif /* CONFIG_IPV6 */
C
Casey Schaufler 已提交
3749 3750
	}
	*secid = s;
3751 3752 3753 3754 3755 3756
	if (s == 0)
		return -EINVAL;
	return 0;
}

/**
3757 3758 3759
 * smack_sock_graft - Initialize a newly created socket with an existing sock
 * @sk: child sock
 * @parent: parent socket
3760
 *
3761 3762
 * Set the smk_{in,out} state of an existing sock based on the process that
 * is creating the new socket.
3763 3764 3765 3766
 */
static void smack_sock_graft(struct sock *sk, struct socket *parent)
{
	struct socket_smack *ssp;
3767
	struct smack_known *skp = smk_of_current();
3768

3769 3770
	if (sk == NULL ||
	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3771 3772 3773
		return;

	ssp = sk->sk_security;
3774
	ssp->smk_in = skp;
3775
	ssp->smk_out = skp;
3776
	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790
}

/**
 * smack_inet_conn_request - Smack access check on connect
 * @sk: socket involved
 * @skb: packet
 * @req: unused
 *
 * Returns 0 if a task with the packet label could write to
 * the socket, otherwise an error code
 */
static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
				   struct request_sock *req)
{
3791
	u16 family = sk->sk_family;
3792
	struct smack_known *skp;
3793
	struct socket_smack *ssp = sk->sk_security;
3794 3795 3796
	struct netlbl_lsm_secattr secattr;
	struct sockaddr_in addr;
	struct iphdr *hdr;
3797
	struct smack_known *hskp;
3798
	int rc;
E
Etienne Basset 已提交
3799
	struct smk_audit_info ad;
3800
#ifdef CONFIG_AUDIT
3801
	struct lsm_network_audit net;
3802
#endif
3803

3804
#if IS_ENABLED(CONFIG_IPV6)
3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815
	if (family == PF_INET6) {
		/*
		 * Handle mapped IPv4 packets arriving
		 * via IPv6 sockets. Don't set up netlabel
		 * processing on IPv6.
		 */
		if (skb->protocol == htons(ETH_P_IP))
			family = PF_INET;
		else
			return 0;
	}
3816
#endif /* CONFIG_IPV6 */
3817

C
Casey Schaufler 已提交
3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
	/*
	 * If there is a secmark use it rather than the CIPSO label.
	 * If there is no secmark fall back to CIPSO.
	 * The secmark is assumed to reflect policy better.
	 */
	if (skb && skb->secmark != 0) {
		skp = smack_from_secid(skb->secmark);
		goto access_check;
	}
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */

3830 3831
	netlbl_secattr_init(&secattr);
	rc = netlbl_skbuff_getattr(skb, family, &secattr);
3832
	if (rc == 0)
3833
		skp = smack_from_secattr(&secattr, ssp);
3834
	else
3835
		skp = &smack_known_huh;
3836 3837
	netlbl_secattr_destroy(&secattr);

C
Casey Schaufler 已提交
3838 3839 3840 3841
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
access_check:
#endif

E
Etienne Basset 已提交
3842
#ifdef CONFIG_AUDIT
3843 3844 3845
	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
	ad.a.u.net->family = family;
	ad.a.u.net->netif = skb->skb_iif;
E
Etienne Basset 已提交
3846 3847
	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
#endif
3848
	/*
3849 3850
	 * Receiving a packet requires that the other end be able to write
	 * here. Read access is not required.
3851
	 */
3852 3853
	rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
	rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
3854 3855 3856 3857 3858 3859 3860
	if (rc != 0)
		return rc;

	/*
	 * Save the peer's label in the request_sock so we can later setup
	 * smk_packet in the child socket so that SO_PEERCRED can report it.
	 */
3861
	req->peer_secid = skp->smk_secid;
3862 3863 3864 3865

	/*
	 * We need to decide if we want to label the incoming connection here
	 * if we do we only need to label the request_sock and the stack will
L
Lucas De Marchi 已提交
3866
	 * propagate the wire-label to the sock when it is created.
3867 3868 3869 3870
	 */
	hdr = ip_hdr(skb);
	addr.sin_addr.s_addr = hdr->saddr;
	rcu_read_lock();
3871
	hskp = smack_host_label(&addr);
3872 3873
	rcu_read_unlock();

3874
	if (hskp == NULL)
3875
		rc = netlbl_req_setattr(req, &skp->smk_netlabel);
3876
	else
3877
		netlbl_req_delattr(req);
3878 3879 3880 3881

	return rc;
}

3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892
/**
 * smack_inet_csk_clone - Copy the connection information to the new socket
 * @sk: the new socket
 * @req: the connection's request_sock
 *
 * Transfer the connection's peer label to the newly created socket.
 */
static void smack_inet_csk_clone(struct sock *sk,
				 const struct request_sock *req)
{
	struct socket_smack *ssp = sk->sk_security;
3893
	struct smack_known *skp;
3894

3895 3896
	if (req->peer_secid != 0) {
		skp = smack_from_secid(req->peer_secid);
3897
		ssp->smk_packet = skp;
3898
	} else
3899
		ssp->smk_packet = NULL;
3900 3901
}

3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913
/*
 * Key management security hooks
 *
 * Casey has not tested key support very heavily.
 * The permission check is most likely too restrictive.
 * If you care about keys please have a look.
 */
#ifdef CONFIG_KEYS

/**
 * smack_key_alloc - Set the key security blob
 * @key: object
D
David Howells 已提交
3914
 * @cred: the credentials to use
3915 3916 3917 3918 3919 3920
 * @flags: unused
 *
 * No allocation required
 *
 * Returns 0
 */
D
David Howells 已提交
3921
static int smack_key_alloc(struct key *key, const struct cred *cred,
3922 3923
			   unsigned long flags)
{
3924 3925
	struct smack_known *skp = smk_of_task(cred->security);

3926
	key->security = skp;
3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940
	return 0;
}

/**
 * smack_key_free - Clear the key security blob
 * @key: the object
 *
 * Clear the blob pointer
 */
static void smack_key_free(struct key *key)
{
	key->security = NULL;
}

3941
/**
3942 3943
 * smack_key_permission - Smack access on a key
 * @key_ref: gets to the object
D
David Howells 已提交
3944
 * @cred: the credentials to use
3945
 * @perm: requested key permissions
3946 3947 3948 3949 3950
 *
 * Return 0 if the task has read and write to the object,
 * an error code otherwise
 */
static int smack_key_permission(key_ref_t key_ref,
3951
				const struct cred *cred, unsigned perm)
3952 3953
{
	struct key *keyp;
E
Etienne Basset 已提交
3954
	struct smk_audit_info ad;
3955
	struct smack_known *tkp = smk_of_task(cred->security);
3956
	int request = 0;
C
Casey Schaufler 已提交
3957
	int rc;
3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970

	keyp = key_ref_to_ptr(key_ref);
	if (keyp == NULL)
		return -EINVAL;
	/*
	 * If the key hasn't been initialized give it access so that
	 * it may do so.
	 */
	if (keyp->security == NULL)
		return 0;
	/*
	 * This should not occur
	 */
3971
	if (tkp == NULL)
3972
		return -EACCES;
E
Etienne Basset 已提交
3973 3974 3975 3976 3977
#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
	ad.a.u.key_struct.key = keyp->serial;
	ad.a.u.key_struct.key_desc = keyp->description;
#endif
3978 3979 3980 3981
	if (perm & KEY_NEED_READ)
		request = MAY_READ;
	if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
		request = MAY_WRITE;
C
Casey Schaufler 已提交
3982 3983 3984
	rc = smk_access(tkp, keyp->security, request, &ad);
	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
	return rc;
3985 3986 3987
}
#endif /* CONFIG_KEYS */

3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014
/*
 * Smack Audit hooks
 *
 * Audit requires a unique representation of each Smack specific
 * rule. This unique representation is used to distinguish the
 * object to be audited from remaining kernel objects and also
 * works as a glue between the audit hooks.
 *
 * Since repository entries are added but never deleted, we'll use
 * the smack_known label address related to the given audit rule as
 * the needed unique representation. This also better fits the smack
 * model where nearly everything is a label.
 */
#ifdef CONFIG_AUDIT

/**
 * smack_audit_rule_init - Initialize a smack audit rule
 * @field: audit rule fields given from user-space (audit.h)
 * @op: required testing operator (=, !=, >, <, ...)
 * @rulestr: smack label to be audited
 * @vrule: pointer to save our own audit rule representation
 *
 * Prepare to audit cases where (@field @op @rulestr) is true.
 * The label to be audited is created if necessay.
 */
static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
{
4015
	struct smack_known *skp;
4016 4017 4018 4019 4020 4021
	char **rule = (char **)vrule;
	*rule = NULL;

	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
		return -EINVAL;

4022
	if (op != Audit_equal && op != Audit_not_equal)
4023 4024
		return -EINVAL;

4025 4026 4027
	skp = smk_import_entry(rulestr, 0);
	if (skp)
		*rule = skp->smk_known;
4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068

	return 0;
}

/**
 * smack_audit_rule_known - Distinguish Smack audit rules
 * @krule: rule of interest, in Audit kernel representation format
 *
 * This is used to filter Smack rules from remaining Audit ones.
 * If it's proved that this rule belongs to us, the
 * audit_rule_match hook will be called to do the final judgement.
 */
static int smack_audit_rule_known(struct audit_krule *krule)
{
	struct audit_field *f;
	int i;

	for (i = 0; i < krule->field_count; i++) {
		f = &krule->fields[i];

		if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
			return 1;
	}

	return 0;
}

/**
 * smack_audit_rule_match - Audit given object ?
 * @secid: security id for identifying the object to test
 * @field: audit rule flags given from user-space
 * @op: required testing operator
 * @vrule: smack internal rule presentation
 * @actx: audit context associated with the check
 *
 * The core Audit hook. It's used to take the decision of
 * whether to audit or not to audit a given object.
 */
static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
				  struct audit_context *actx)
{
4069
	struct smack_known *skp;
4070 4071
	char *rule = vrule;

4072 4073
	if (unlikely(!rule)) {
		WARN_ONCE(1, "Smack: missing rule\n");
4074 4075 4076 4077 4078 4079
		return -ENOENT;
	}

	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
		return 0;

4080
	skp = smack_from_secid(secid);
4081 4082 4083 4084 4085 4086

	/*
	 * No need to do string comparisons. If a match occurs,
	 * both pointers will point to the same smack_known
	 * label.
	 */
4087
	if (op == Audit_equal)
4088
		return (rule == skp->smk_known);
4089
	if (op == Audit_not_equal)
4090
		return (rule != skp->smk_known);
4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107

	return 0;
}

/**
 * smack_audit_rule_free - free smack rule representation
 * @vrule: rule to be freed.
 *
 * No memory was allocated.
 */
static void smack_audit_rule_free(void *vrule)
{
	/* No-op */
}

#endif /* CONFIG_AUDIT */

4108 4109 4110 4111 4112 4113 4114 4115 4116 4117
/**
 * smack_ismaclabel - check if xattr @name references a smack MAC label
 * @name: Full xattr name to check.
 */
static int smack_ismaclabel(const char *name)
{
	return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
}


4118
/**
4119 4120 4121 4122 4123 4124 4125 4126 4127
 * smack_secid_to_secctx - return the smack label for a secid
 * @secid: incoming integer
 * @secdata: destination
 * @seclen: how long it is
 *
 * Exists for networking code.
 */
static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
4128
	struct smack_known *skp = smack_from_secid(secid);
4129

4130
	if (secdata)
4131 4132
		*secdata = skp->smk_known;
	*seclen = strlen(skp->smk_known);
4133 4134 4135
	return 0;
}

4136
/**
4137 4138 4139 4140 4141 4142 4143
 * smack_secctx_to_secid - return the secid for a smack label
 * @secdata: smack label
 * @seclen: how long result is
 * @secid: outgoing integer
 *
 * Exists for audit and networking code.
 */
4144
static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4145
{
4146 4147 4148 4149 4150 4151
	struct smack_known *skp = smk_find_entry(secdata);

	if (skp)
		*secid = skp->smk_secid;
	else
		*secid = 0;
4152 4153 4154
	return 0;
}

4155
/**
4156
 * smack_release_secctx - don't do anything.
4157 4158
 * @secdata: unused
 * @seclen: unused
4159 4160 4161 4162 4163 4164 4165
 *
 * Exists to make sure nothing gets done, and properly
 */
static void smack_release_secctx(char *secdata, u32 seclen)
{
}

4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186
static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
{
	return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
}

static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
{
	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
}

static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
{
	int len = 0;
	len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);

	if (len < 0)
		return len;
	*ctxlen = len;
	return 0;
}

4187 4188 4189
struct security_operations smack_ops = {
	.name =				"smack",

4190
	.ptrace_access_check =		smack_ptrace_access_check,
4191
	.ptrace_traceme =		smack_ptrace_traceme,
4192 4193 4194 4195 4196 4197 4198 4199
	.syslog = 			smack_syslog,

	.sb_alloc_security = 		smack_sb_alloc_security,
	.sb_free_security = 		smack_sb_free_security,
	.sb_copy_data = 		smack_sb_copy_data,
	.sb_kern_mount = 		smack_sb_kern_mount,
	.sb_statfs = 			smack_sb_statfs,

4200
	.bprm_set_creds =		smack_bprm_set_creds,
4201 4202
	.bprm_committing_creds =	smack_bprm_committing_creds,
	.bprm_secureexec =		smack_bprm_secureexec,
4203

4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220
	.inode_alloc_security = 	smack_inode_alloc_security,
	.inode_free_security = 		smack_inode_free_security,
	.inode_init_security = 		smack_inode_init_security,
	.inode_link = 			smack_inode_link,
	.inode_unlink = 		smack_inode_unlink,
	.inode_rmdir = 			smack_inode_rmdir,
	.inode_rename = 		smack_inode_rename,
	.inode_permission = 		smack_inode_permission,
	.inode_setattr = 		smack_inode_setattr,
	.inode_getattr = 		smack_inode_getattr,
	.inode_setxattr = 		smack_inode_setxattr,
	.inode_post_setxattr = 		smack_inode_post_setxattr,
	.inode_getxattr = 		smack_inode_getxattr,
	.inode_removexattr = 		smack_inode_removexattr,
	.inode_getsecurity = 		smack_inode_getsecurity,
	.inode_setsecurity = 		smack_inode_setsecurity,
	.inode_listsecurity = 		smack_inode_listsecurity,
4221
	.inode_getsecid =		smack_inode_getsecid,
4222 4223 4224 4225 4226 4227 4228

	.file_permission = 		smack_file_permission,
	.file_alloc_security = 		smack_file_alloc_security,
	.file_free_security = 		smack_file_free_security,
	.file_ioctl = 			smack_file_ioctl,
	.file_lock = 			smack_file_lock,
	.file_fcntl = 			smack_file_fcntl,
4229 4230
	.mmap_file =			smack_mmap_file,
	.mmap_addr =			cap_mmap_addr,
4231 4232 4233 4234
	.file_set_fowner = 		smack_file_set_fowner,
	.file_send_sigiotask = 		smack_file_send_sigiotask,
	.file_receive = 		smack_file_receive,

4235
	.file_open =			smack_file_open,
4236

4237
	.cred_alloc_blank =		smack_cred_alloc_blank,
4238
	.cred_free =			smack_cred_free,
D
David Howells 已提交
4239
	.cred_prepare =			smack_cred_prepare,
4240
	.cred_transfer =		smack_cred_transfer,
4241 4242
	.kernel_act_as =		smack_kernel_act_as,
	.kernel_create_files_as =	smack_kernel_create_files_as,
4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257
	.task_setpgid = 		smack_task_setpgid,
	.task_getpgid = 		smack_task_getpgid,
	.task_getsid = 			smack_task_getsid,
	.task_getsecid = 		smack_task_getsecid,
	.task_setnice = 		smack_task_setnice,
	.task_setioprio = 		smack_task_setioprio,
	.task_getioprio = 		smack_task_getioprio,
	.task_setscheduler = 		smack_task_setscheduler,
	.task_getscheduler = 		smack_task_getscheduler,
	.task_movememory = 		smack_task_movememory,
	.task_kill = 			smack_task_kill,
	.task_wait = 			smack_task_wait,
	.task_to_inode = 		smack_task_to_inode,

	.ipc_permission = 		smack_ipc_permission,
4258
	.ipc_getsecid =			smack_ipc_getsecid,
4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290

	.msg_msg_alloc_security = 	smack_msg_msg_alloc_security,
	.msg_msg_free_security = 	smack_msg_msg_free_security,

	.msg_queue_alloc_security = 	smack_msg_queue_alloc_security,
	.msg_queue_free_security = 	smack_msg_queue_free_security,
	.msg_queue_associate = 		smack_msg_queue_associate,
	.msg_queue_msgctl = 		smack_msg_queue_msgctl,
	.msg_queue_msgsnd = 		smack_msg_queue_msgsnd,
	.msg_queue_msgrcv = 		smack_msg_queue_msgrcv,

	.shm_alloc_security = 		smack_shm_alloc_security,
	.shm_free_security = 		smack_shm_free_security,
	.shm_associate = 		smack_shm_associate,
	.shm_shmctl = 			smack_shm_shmctl,
	.shm_shmat = 			smack_shm_shmat,

	.sem_alloc_security = 		smack_sem_alloc_security,
	.sem_free_security = 		smack_sem_free_security,
	.sem_associate = 		smack_sem_associate,
	.sem_semctl = 			smack_sem_semctl,
	.sem_semop = 			smack_sem_semop,

	.d_instantiate = 		smack_d_instantiate,

	.getprocattr = 			smack_getprocattr,
	.setprocattr = 			smack_setprocattr,

	.unix_stream_connect = 		smack_unix_stream_connect,
	.unix_may_send = 		smack_unix_may_send,

	.socket_post_create = 		smack_socket_post_create,
4291
#ifndef CONFIG_SECURITY_SMACK_NETFILTER
4292
	.socket_bind =			smack_socket_bind,
4293
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
4294 4295
	.socket_connect =		smack_socket_connect,
	.socket_sendmsg =		smack_socket_sendmsg,
4296 4297 4298 4299 4300 4301 4302
	.socket_sock_rcv_skb = 		smack_socket_sock_rcv_skb,
	.socket_getpeersec_stream =	smack_socket_getpeersec_stream,
	.socket_getpeersec_dgram =	smack_socket_getpeersec_dgram,
	.sk_alloc_security = 		smack_sk_alloc_security,
	.sk_free_security = 		smack_sk_free_security,
	.sock_graft = 			smack_sock_graft,
	.inet_conn_request = 		smack_inet_conn_request,
4303
	.inet_csk_clone =		smack_inet_csk_clone,
4304

4305 4306 4307 4308 4309 4310
 /* key management security hooks */
#ifdef CONFIG_KEYS
	.key_alloc = 			smack_key_alloc,
	.key_free = 			smack_key_free,
	.key_permission = 		smack_key_permission,
#endif /* CONFIG_KEYS */
4311 4312 4313 4314 4315 4316 4317 4318 4319

 /* Audit hooks */
#ifdef CONFIG_AUDIT
	.audit_rule_init =		smack_audit_rule_init,
	.audit_rule_known =		smack_audit_rule_known,
	.audit_rule_match =		smack_audit_rule_match,
	.audit_rule_free =		smack_audit_rule_free,
#endif /* CONFIG_AUDIT */

4320
	.ismaclabel =			smack_ismaclabel,
4321
	.secid_to_secctx = 		smack_secid_to_secctx,
4322
	.secctx_to_secid = 		smack_secctx_to_secid,
4323
	.release_secctx = 		smack_release_secctx,
4324 4325 4326
	.inode_notifysecctx =		smack_inode_notifysecctx,
	.inode_setsecctx =		smack_inode_setsecctx,
	.inode_getsecctx =		smack_inode_getsecctx,
4327 4328
};

4329

4330
static __init void init_smack_known_list(void)
4331
{
4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352
	/*
	 * Initialize rule list locks
	 */
	mutex_init(&smack_known_huh.smk_rules_lock);
	mutex_init(&smack_known_hat.smk_rules_lock);
	mutex_init(&smack_known_floor.smk_rules_lock);
	mutex_init(&smack_known_star.smk_rules_lock);
	mutex_init(&smack_known_invalid.smk_rules_lock);
	mutex_init(&smack_known_web.smk_rules_lock);
	/*
	 * Initialize rule lists
	 */
	INIT_LIST_HEAD(&smack_known_huh.smk_rules);
	INIT_LIST_HEAD(&smack_known_hat.smk_rules);
	INIT_LIST_HEAD(&smack_known_star.smk_rules);
	INIT_LIST_HEAD(&smack_known_floor.smk_rules);
	INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
	INIT_LIST_HEAD(&smack_known_web.smk_rules);
	/*
	 * Create the known labels list
	 */
4353 4354 4355 4356 4357 4358
	smk_insert_entry(&smack_known_huh);
	smk_insert_entry(&smack_known_hat);
	smk_insert_entry(&smack_known_star);
	smk_insert_entry(&smack_known_floor);
	smk_insert_entry(&smack_known_invalid);
	smk_insert_entry(&smack_known_web);
4359 4360
}

4361 4362 4363 4364 4365 4366 4367
/**
 * smack_init - initialize the smack system
 *
 * Returns 0
 */
static __init int smack_init(void)
{
D
David Howells 已提交
4368
	struct cred *cred;
4369
	struct task_smack *tsp;
D
David Howells 已提交
4370

4371 4372 4373
	if (!security_module_enable(&smack_ops))
		return 0;

4374 4375
	smack_enabled = 1;

4376 4377 4378 4379
	smack_inode_cache = KMEM_CACHE(inode_smack, 0);
	if (!smack_inode_cache)
		return -ENOMEM;

4380 4381
	tsp = new_task_smack(&smack_known_floor, &smack_known_floor,
				GFP_KERNEL);
4382 4383
	if (tsp == NULL) {
		kmem_cache_destroy(smack_inode_cache);
4384
		return -ENOMEM;
4385
	}
4386

4387 4388 4389 4390 4391
	printk(KERN_INFO "Smack:  Initializing.\n");

	/*
	 * Set the security state for the initial task.
	 */
D
David Howells 已提交
4392
	cred = (struct cred *) current->cred;
4393
	cred->security = tsp;
4394

4395 4396
	/* initialize the smack_known_list */
	init_smack_known_list();
4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411

	/*
	 * Register with LSM
	 */
	if (register_security(&smack_ops))
		panic("smack: Unable to register with kernel.\n");

	return 0;
}

/*
 * Smack requires early initialization in order to label
 * all processes and objects when they are created.
 */
security_initcall(smack_init);